Journal of Dairy Science Flashcards

Question

Antimicrobial activities of polyhexamethylene biguanide against biofilm-producing Prototheca bovis causing bovine mastitis Fidelis et al., 2023

Answer 1

* We observed that PHMB (MIC90: ≥2 µg/mL and MAC90: ≥4 µg/mL) and chlorhexidine gluconate (MIC90 and MAC90: ≥2 µg/mL) presented the highest antimicrobial activity against P. bovis isolates, followed by sodium dichloroisocyanurate (MIC90 and MAC90: ≥1,400 µg/mL), sodium hypochlorite (MIC90 and MAC90: ≥2,800 µg/mL), and povidone-iodine (MIC90 and MAC90: ≥3,200 µg/mL). * Concerning P. blaschkeae isolates, PHMB (MIC and MAC ≥1 µg/mL) and chlorhexidine gluconate (MIC and MAC ≥1 µg/mL) were the disinfectants that presented the lowest concentration values required to inhibit the isolates. * These findings suggest that PHMB has the potential to be used for teat and milking-equipment disinfection for the prevention of mastitis-causing Prototheca spp. in dairy herds.

Answer 2

* Despite minor changes in postabsorptive energetics and leukocyte dynamics, abomasal starch infusions and the subsequent hindgut acidosis had little or no meaningful effects on biomarkers of immune activation or production variables.

Answer 3

o (1) thermoneutral (TN) conditions and fed a control diet (TN-CON; n = 8), o (2) TN and fed a diet with AP (10 g antioxidant; n = 8), o (3) heat stress (HS) and fed a control diet (HS-CON; n = 8), or o (4) HS and fed a diet with AP (HS-AP; n = 8). There were no effects of AP on body temperature indices or production. * Circulating serum amyloid A tended to be and lipopolysaccharide binding protein was increased by HS, but neither acute-phase protein was affected by AP. Overall, AP supplementation appeared to marginally alter metabolism but did not meaningfully alter inflammation during HS.

Answer 4

* The lack of consistent responses in inflammatory biomarkers suggests that FR and abaomasal resistant starch did not meaningfully affect intestinal barrier function. Thus, future research evaluating the effects of hindgut acidosis and FR using more intense insults and direct metrics of intestinal barrier function is warranted.

Answer 5

* Although milk production was decreased in HS cows compared with CL cows, the incidence of uterine disease and content of total or pathogenic bacteria in vaginal mucus on d 7 or d 21 postpartum was not affected by treatment. * Whole blood was collected on d 21 and subjected to in vitro stimulation with lipopolysaccharide. Lipopolysaccharide-induced accumulation of IL-1β, IL-10, and MIP-1α was greater in blood collected from HS cows compared with CL cows. * Our results imply that prepartum HS during late pregnancy has carry-over effects on postpartum innate immunity, which may contribute to the increased incidence of uterine disease observed in cows exposed to prepartum HS.

Answer 6

* Results showed that heat production and VO2 were linearly and positively associated with HR, but this relationship largely varied between individual cows. Within the range tested, O2P (the oxygen pulse, which represents the amount of oxygen that is consumed by the cow per heartbeat) was unaffected by temperature, but we detected a tendency for an interaction of O2P with the temperature range tested during the night versus during the day. * Standing and eating slightly increased O2P (1.0 and 2.5%) compared with lying down and idling, respectively, whereas rumination increased O2P by 5.1% compared with idling. * The energy cost of eating and ruminating over idling was 223 ± 11 and 45 ± 6 kJ/kg0.75 per day, respectively, whereas the energy cost of standing over lying down was 53 ± 6 kJ/kg0.75 per day. * We concluded that O2P in dairy cows was slightly affected by both animal posture and activity, but remained unaffected by air temperature within 8 to 32°C. * Nonlinearity of the relationship between the O2P and air temperature suggests that caution is required extrapolating O2P beyond the temperature range evaluated in our experiment.

Answer 7

The combined addition of 3-NOP (inhibit methane, but increase hydrogen production) and vitamin B12 (increase proprionate production) significantly increased the concentration of propionate and reduced the concentration of acetate and the acetate to propionate ratio. The results indicated that 3-NOP combined with vitamin B12 could alleviate rumen hydrogen emission and enhance the inhibition of methane emission compared with 3-NOP alone.

Answer 8

Protein disulfide isomerase family A member 3 (PDIA3) plays a vital role in modulating various cell biological functions under physiological and pathological conditions  PDIA3 overexpression was also found to positively regulate the synthesis and secretion of alpha-casein, beta-casein, and kappa-casein, whereas knockdown of this gene showed the opposite effects.  Our findings revealed significant genetic effects of PDIA3 on milk composition traits, and the identified SNP and the haplotype block might be used as genetic markers for dairy cow selected breeding.

Answer 9

 Compared with HO, crossbred carcasses were 7 to 12% heavier depending on the breed of sire, were graded + 0.12 to + 0.28 units higher for fleshiness and + 0.26 to + 0.30 units higher for fatness and fetched an 8 to 11% higher price.  Compared with purebred HO, carcasses from crossbreds had 15 to 24% higher value ( euro 84 to euro 133 more per cow), with crossbred cows sired by MO showing the greatest values.  Compared with the HO cows, the crossbred cows had a 37% lower risk of being urgently removed from the herd, which raises welfare concerns and may reduce the salvage value of cull cows.  Because cull cows represent a supplemental source of income for dairy farmers, the greater overall value of crossbred cull cows should be taken into ac-count in evaluating the economic effectiveness of cross-schemes.

Answer 10

 Overall, the abDCT group was determined to have a significantly higher milk yield over 305 d in milk in the subsequent lactation (increase of 6.18%), compared with the noDCT group (increase of 4.29%).  Both groups (abDCT and noDCT) demonstrated a decrease in the first SCC after calving compared with the SCC before dry-off, although the treated cows had a significantly higher reduction.  Regarding the different antibiotic groups, with exception of the rifaximin treated cows, all antibiotic groups showed a significant difference from not treated cows with respect to SCC.  Additionally, we were able to demonstrate that cows with IMI before dry-off had a 2.073 times higher chance of an increased SCC (>200,000 cells/mL) after calving.  Neither the IMG be-fore drying off nor the type of DCT had a significant influence on the probability of developing clinical mastitis within 30 or 90 d in milk. Only a small number of treatments was accompanied with a bacteriological examination before drying off. However, the existing data in this study indicates that the intramammary infection status before dry-off in combination with different dry cow treatments influences udder health and milk yield after calving.

Answer 11

 In conclusion, voluntary soaker use related positively to the THI, but no major productive, physiological, or behavioral differences were observed between soaking treatments. Furthermore, we found that voluntary soaker use is highly variable among cows and it was related positively to milk yield, where higher producing cows used the soaker more frequently.

Answer 12

In summary, our study supports that decisions on AMU cannot be reduced to the individual prescriber's behavior, nor to a strict medical judgment. Antimicrobial use for dairy cattle needs to be understood as taking form in relationships in which both veterinarians and farmers are active parts.

Answer 13

To conclude, overall, the routine dairy herd improvement analysis (DHI) + BHB [determined by mid-infrared] + milk fatty acids [determined by mid-infrared] model allowed to predict metabolic status during early lactation from d 9 and 21. Accordingly, these parameters show potential for routine prediction of metabolic status.

Answer 14

The addition of a second PGF treatment on d 7 and 8 of a 7-d Ovsynch protocol increased luteal regression and decreased mean P4 at G2. Cows treated with PGF2 alpha 2 times 24 h apart showed greater P/AI, compared with cows treated with an increased dose of PGF2 alpha.

Answer 15

Lactational incidence (LI) risk of clinical hypocalcemia increased with parity from 0.1% for parity 1 to 13% for parity >= 5 cows. The marked increase suggests profound differences in metabolism with increased parity. The LI of clinical mastitis was 17.4%. The odds of mastitis increased with parity to 2.5 times greater in parity >= 5 than in parity 1. The LI of lameness increased with parity; specifically, the odds of lameness was 5.6 times greater for parity >= 5 than parity 1. Dystocia incidence was 8.7% and greatest for parity 1 cows. The LI of retained placenta was 7.4% and increased with parity, with the odds for parity >= 5 2.3 times greater than for parity 1. The LI of metritis was 10% and of endometritis 14%, with the greatest odds in parity 1. The LI of clinical ketosis was 3.3% with a marked increase in odds with parity. The prevalence of subclinical ketosis was 26.8% with only cows in parity 1 having lower odds than other parities. Parity >= 5 cows had greater odds (odds ratio = 1.7) of respiratory disease than parity 1 cows, which were lesser than other pari-ties. Metabolite concentrations were evaluated in 5,154 Holstein cows in the precalving, calving, and immediate postcalving data sets. Concentrations of beta-hydroxybutyrate (BHB) and nonesterified fatty acids increased with parity on d 1 to 3 of lactation and at peak lactation. On d 1 to 3 after calving differences in glucose, nonesterified fatty acids, and BHB indicated a greater reliance on mobilized lipid to export energy to peripheral tissues as BHB for greater parity cows. Differences in concentrations among parity groups were marked at times, for example >0.20 mM in Ca for parity 1 and 2 to parity >= 5 and >0.33 mM for all older parities compared with parity 1 for P on the day of calving. We found marked differences in concentrations of metabolites with parity that are consistent with reduced reproduction, health, and body condition for higher parity cows. These unfavorable differences in metabolism in Ca, P, glucose, and cholesterol concentrations for higher parity cows also complement the often-substantial differences in disease risk with parity and suggest a need to carefully consider the parity structure in study design. Managers and advisors will need to consider methods to reduce risk of health disorders tailored to cows of different ages.

Answer 16

Because of their low cost, quickness, and ease of measurement, GGT and TP were good indicators of colostrum intake in calves arriving at rearing facilities beyond 14 d of age.

Answer 17

 Cows with high IgG showed higher concentrations of glucose compared with low IgG.  Cows with high IgA had higher concentrations of cholesterol, reactive oxygen and nitrogen species, oxidant status index, and total protein, whereas beta-hydroxybutyrate and glucose were lower compared with low IgA. The great variability observed in colostrum variables suggests that colostrogenesis is a complex and multifactorial process. However, our results suggest that greater availability of antioxidants during late gestation could support the production of higher volumes of colostrum, which needs to be explored in future trials.

Answer 18

It can be concluded that FM treatment slightly reduced inflammation (lower haptoglobin, higher albumin) and diminished the risk for metritis in primiparous cows, improved metabolic profile in multiparous cows, and reduced expressions of pain in all cows.

Answer 19

We conclude that a single transdermal administration of FM in early postpartum dairy cows on farms at risk for excessive postpartum inflammation slightly increased milk, milk fat, and milk protein yields in PRIM cows and decreased these variables in MULT cows. Milk urea and somatic cell count were not affected by treatment. No differences in culling risk, first-service conception risk, or days open were observed

Answer 20

The administration of dexamethasone resulted in changes in behavioral measurements, which could suggest a reduction in discomfort; however, due to the reduction in milk yield for the first month follow-ing calving, DEX administration may not be applicable for typical farm use. Additional research is needed to investigate treatments for cows experiencing dystocia without detrimental effects on milk yield.

Answer 21

Based on the results of the study, we found merit (12s shorter) in applying 60 s of mechanical pre-stimulation at a.m. milking from a milking duration perspective. However, the strategy was not as successful for the p.m. milking. Analysis of the milk flowrate profiles recorded during the study suggest potential utility in employing different machine settings for various milkings based on anticipated yield and level of udder fill. Treatment had no effect on a.m./p.m. milk yields, average milk flowrates or peak milk flowrates.

Answer 22

Avoidance of gross overconsumption of energy prepartum, particularly during the far-off period, appears best to reduce systemic inflammatory signals and improve liver function.

Answer 23

Supplementing transition cow TMR with active dry yeast (CNCM I-1079) improved milk production (39.0 ± 2.4 vs. 36.7 ± 2.3 kg/d) and nd tended to produce more energy-corrected milk with better feed efficiency; markers of inflammation (SAA and TNFa tended to increase) were also influenced by ADY treatment, though the immunological effect was inconsistent.  No difference in colostrum IgG, IgA, and IgM was observed between treatments. There was no difference in plasma glucose, serum nonesterified fatty acid, serum β-hydroxybutyrate, Hp, IL-6, or IL-18 due to ADY treatment. Supplementing transition cow TMR with ADY (CNCM I-1079) improved milk production and tended to improve efficiency in early lactation; markers of inflammation were also influenced by ADY treatment, though the immunological effect was inconsistent.

Answer 24

 In conclusion, feeding NT increased milk fat production of first-lactation cows but did not affect overall productive performance.  However, supplementation with NT improved induced granulocyte oxidative burst. This may explain the greater glucose utilization by cows fed NT rather than CTL during feed restriction.

Answer 25

In summary, H-PVL cows were more susceptible to subclinical mastitis than non-infected and low-proviral-load cows, and mastitis due to BLV infection was projected to cause significant economic losses.

Answer 26

 The positivity rate of bacteria in the 160 lung samples was 31.77%, including Trueperella pyogenes (9.37%), Pasteurella multocida (8.35%), Histophilus somni (4.48%), Mannheimia haemolytica (2.44%), and other bacteria (7.13%).  The positivity rate of Mycoplasma spp. was 38.9%, including M. bovis (7.74%), M. dispar (11.61%), M. bovirhinis (7.94%), M. alkalescens (6.11%), M. arginini (0.81%), and undetermined species (4.68%).  Six species of viruses were detected with a positivity rate of 29.33%, including bovine herpesvirus-1 (BoHV-1; 13.25%), bovine respiratory syncytial virus (BRSV; 5.50%), bovine viral diarrhea virus (BVDV; 4.89%), bovine parainfluenza virus type-3 (BPIV-3; 4.28%), bovine parainfluenza virus type-5 (1.22%), and bovine coronavirus (2.24%). Mixed infections among bacteria (73.75%), viruses (50%), and M. bovis (23.75%) were the major features of BRDC in these cattle herds. molecular epidemiology indicated that the occurrence rate of currently prevalent pathogens in BRDC was 46.15% (6/13) for BoHV-1.2b and 53.85% (7/13) for BoHV-1.2c, 53.3% (8/15) for BVDV-1b and 46.7% (7/15) for BVDV-1d, 29.41% (5/17) for BPIV-3a and 70.59% (12/17) for BPIV-3c, 100% (2/2) for BRSV gene subgroup IX, 91.67% (33/36) for P. multocida serotype A, and 8.33% (3/36) for P. multocida serotype D. Our research discovered new subgenotypes for BoHV-1.2c, BRSV gene subgroup IX, and P. multocida serotype D in China's cattle herds. In the BRDC cases, bovine suppurative or caseous necrotizing pneumonia was highly related to BVDV [odds ratio (OR) = 4.18; 95% confidence interval (95% CI): 1.6-10.7], M. bovis (OR = 2.35; 95% CI: 1.1-4.9), H. somni (OR = 8.2; 95% CI: 2.6-25.5), and T. pyogenes (OR = 13.92; 95% CI: 5.8-33.3). The risk factor analysis found that dairy calves <3 mo and beef calves >3 mo (OR = 5.39; 95% CI: 2.7-10.7) were more susceptible to BRDC. Beef cattle were more susceptible to bovine suppurative or caseous necrotizing pneumonia than dairy cattle (OR = 2.32; 95% CI: 1.2-4.4). The risk factor analysis found that dairy calves <3 mo and beef calves >3 mo (OR = 5.39; 95% CI: 2.7-10.7) were more susceptible to BRDC. These epidemiological data and the new pathogen subgenotypes will be helpful in formulating strategies of control and prevention, developing new vaccines, improving clinical differential diagnosis by necropsy, predicting the most likely pathogen, and justifying antimicrobial use.

Answer 27

Unexpectedly, intrauterine infusion of cows with a lower dose (10^6 cfu)of bacteria (F. necrophorium, E. coli, T. pyogenes) was more effective than a higher dose (10^9), indicating that the bacterial load may affect metritis incidence in a nonlinear manner.

Answer 28

Our results suggest that dairy producers provide similar care between male and female calves, but some male calves experience challenges due to milk feeding and marketing practices. Feedback from calf buyers along with continued support and guidance from herd veterinarians and the Code of Practice may motivate dairy producers to improve male calf care.

Answer 29

The decrease in milk yield induced by incomplete milking is rapid and associated with a decrease in mammary epithelial cell activity and a decrease in the number of secretory epithelial cells. The results of this experiment provide only limited support for the hypothesis that modulation of the mammary gland's responsiveness to PRL is part of the mechanism by which local factors, such as incomplete milking, modulate milk synthesis.

Answer 30

 calves in long term colostrum group had faster resolution of diarrhea compared with calves in the CON group  the LTC treatment grew 98 g/d more than calves in the CON group.  there was an association between both days to enrollment since facility arrival and body weight and resolution of diarrhea, where calves who were at the facility longer before enrollment and heavier at the onset of diarrhea, resolved diarrhea quicker.  In addition, calves with a fecal score of 3 at enrollment took longer to resolve their case of diarrhea

Answer 31

 Treatment did not affect calf body weight, beta-hydroxybutyrate, or glucose concentrations.  For apparent efficiency of IgG absorption, treatment interacted with the dam's prepartum body condition score. Where the dam's body condition score was ≤3.25, IgG absorption was reduced in calves born from CHOL45 dams as compared with calves from either CHOL30 or CON dams.  Calves from CHOL30 dams had a lesser oxidative stress index (OSi) than calves from CON dams.  Haptoglobin concentrations were less in heifer calves from CHOL45 dams as compared with heifers from CON dams.  The dam's prepartum NEFA concentration interacted with treatment. When dam NEFA was minimal, calves from CHOL45 and CHOL30 dams had greater or tended to have greater NEFA, respectively. Conversely, when dam NEFA was greater, calves from CHOL30 and CHOL45 dams had lesser or tended to have lesser NEFA than calves from CON dams, respectively.  For vaccine response, treatment interacted with the dam's prepartum OSi. Among calves born from dams with a greater OSi, calves from CHOL45 and CHOL30 dams had lesser bovine respiratory syncytial virus-specific IgA concentrations in nasal secretions as compared with CON Prenatal RPC supplementation during late gestation affected IgG absorption, neonatal calf metabolism, and vaccine response with some effects dependent on the dam's prepartum parameters.

Answer 32

 Milk samples from pasture had lower levels of 14 compounds (with fumarate being the most depressed metabolite) and greater levels of 15 compounds (with methanol and hippurate being the most elevated metabolites).  Results indicate that milk 1H NMR spectra are promising to identify milk produced in different conditions.  Also, our study highlights that grazing is associated with significant changes of milk metabolic profile, suggesting the potential use of several metabolites as indicators of farm management.

Answer 33

 Results from this study suggest that the current milk withhold recommendation for dairy cattle administered ASA may need revision to 120 h (5 d) and that ASA administration may mitigate postpartum inflammation through reduction in prostaglandin production for up to 12 h after treatment.

Answer 34

 Drinking speed and MR intake were the main factors to predict calf disease in calves fed ad libitum.  The number of unrewarded visits to the milk feeder and MR intake were the main factors to predict calf disease in restricted-fed calves. Despite the relatively small sample size, the results provide strong evidence that daily feeding behavior data from AMF can be used to identify calves at risk for disease.

Answer 35

 Overall, maternal RPC supplementation during late gestation suggests a positive effect on immunity, in that colostrum from RPC-fed dams increased efficiency of IgG absorption and maternal supplementation with RPC during late gestation, regardless of colostrum source, attenuated responses to LPS challenges.  Note: lipopolysaccharide (LPS) challenges – provide researchers with a robust and safe way to test anti-inflammatory compounds under controlled conditions, before moving on to testing in patients

Answer 36

 We found that calves with 2 of the following findings cough, unilateral or bilateral ear droop or head tilt, or increased rectal temperature ≥39.7°C were considered positive and had a 31% chance of having active BRD. Without at least 2 of these 2 findings, a calf had a 100% chance of not having active BRD.  At the batch level, we found that a batch with ≥3 positive calves among 10 calves sampled 2 wk after arrival at the fattening unit had a 94% chance of having an active BRD prevalence ≥10%.  A batch with <3 positive calves had a 95% chance of not having an active BRD prevalence ≥10%.

Answer 37

 Herd-level factors that were associated with the presence of teat warts on a farm were the proportion of cows with poor teat ends as well as conventional milking systems compared with milking robots.  At a cow level, teat warts were associated with high somatic cell counts.  Herds with poor depth (<5 cm) of bedding material and cows with days in milk less than 60 d had increased odds for udder edema.  First-lactating cows had higher odds for udder thigh dermatitis.  Freestall housing and comfort rubber mats were identified as risk factors for udder cleft dermatitis on a herd level. In conclusion, although most nonmastitis udder diseases were rarely observed in this study, some herd management practices and cow factors were associated with their presence on a farm or cow level. Future studies are needed to further investigate risk factors for each disease in more detail.

Answer 38

 Nitrogen excretion (as % of N intake) in milk, urine, and feces was not altered by treatments.  Feeding CAP increased yields of 3.5% fat-corrected milk, fat, protein, and lactose.  No differences were detected on respiration rate, rectal temperature, and skin temperature of cows.  A feed additive containing encapsulated pepper fed at 0.75 or 1.5 g/d can improve yield of fat-corrected milk and milk solids by increasing feed intake without affecting nutrient digestibility and body temperature of lactating cows during the hot season.

Answer 39

 Dry matter intake, milk production, and milk composition were not affected by BTC supplementation, except for milk fat content that tended to be increased in BTC, compared with CON.  Daily CH4 emission (measured using the GreenFeed system) was linearly decreased by up to 7.5% with increasing doses of BTC.  Supplementation of BTC resulted in a quadratic decrease of serum β-hydroxybutyrate in all cows, and a linear decrease of serum insulin concentration in primiparous but not in multiparous cows.  Nutrient utilization and other blood parameters (e.g., blood cells count) were not affected by BTC in the current study.  The reduction of enteric CH4 emission demonstrates a moderate mitigation effect on carbon footprint of milk by BTC supplementation.  These results must be further investigated and confirmed in longer-term experiments. Supplementation of BTC resulted in a quadratic decrease of serum β-hydroxybutyrate in all cows, and a linear decrease of serum insulin concentration in primiparous but not in multiparous cows. Nutrient utilization and other blood parameters (e.g., blood cells count) were not affected by BTC in the current study. The reduction of enteric CH4 emission demonstrates a moderate mitigation effect on carbon footprint of milk by BTC supplementation. These results must be further investigated and confirmed in longer-term experiments.

Answer 40

 Fertilization failure (15.8%) and embryonic arrest before the morula stage (10.3%) were the major developmental events contributing to first-week pregnancy failures.  Embryo elongation failure of 7% contributed to pregnancy failure during the second week.  The risk factors for pregnancy success that were related to the cows included interval between calving and insemination, and d-7 plasma progesterone concentrations, whereas insemination sire was associated with pregnancy outcome.

Answer 41

 Supplementation did not affect colostral or calf IgG concentrations.  In pregnant cows already receiving adequate vitamin A, supplementation of β-carotene increased concentration of beta-carotene in colostrum, altered colostrum color, and increased serum beta-carotene in calves at birth.

Answer 42

 Regression results showed that larger farms tended to achieve a better animal welfare index (AWI) than smaller farms in our data set.  Although this study focused on the effect of herd size, it is not the only factor affecting animal welfare levels on individual farms. Other variables that we included in the regression to describe the AWI indicate that the knowledge and skills of the farm manager and the amount of time that farms can devote to animals have a positive effect on the AWI.

Answer 43

 our study provides evidence that fetal loss is heritable enough to make genetic selection for reducing fetal loss and improving pregnancy maintenance feasible.  In addition, our results suggest that fetal loss is largely independent from current traits used to select for cow fertility, and thus current breeding efforts have unfortunately little effect on reducing the incidence of fetal loss.

Answer 44

 Noninfectious lesions were found to be more prevalent than infectious lesions in this system type.  The most prevalent lesion types during both grazing and housing periods were white line separation, sole hemorrhages and overgrown claws; all remaining lesions had a cow-level prevalence of less than 15%.  The cow-level prevalence of alarm lesions was 19% during the grazing period and 25% during the housing period; the most prevalent alarm lesion was sole ulcers during both periods. We found significantly more foreign bodies within the hoof sole (grazing = 14%, housing = 7%) and overgrown claws (grazing = 71%, housing = 55%) during the grazing period compared with the housing period. Cows with foul of the foot, sole ulcer, white line abscess, toe necrosis or an amputated claw had higher odds of being more severely lame, compared with mildly lame. The strongest correlation between lesions were between toe necrosis and digital dermatitis (r = 0.40), overgrown claws and corkscrew claws (r = 0.33), and interdigital hyperplasia and digital dermatitis (r = 0.31) at herd level.  At the cow level, the strongest correlation was between overgrown claws and corkscrew claws (r = 0.27), and digital dermatitis and heel erosion (r = 0.22).  The farmers' perception of the presence of digital dermatitis (and lameness) was significantly correlated with the actual presence of digital dermatitis recorded. Additional risk factors for the presence of digital dermatitis were cow track and verge width near the collecting yard, and stone presence on the cow tracks.

Answer 45

 Hyperketonemia in multiparous cows was associated with greater incidence of metabolic abnormalities (hypomagnesemia, hypocalcemia, and elevated NEFA and urea).  Hyperketonemia in primiparous and multiparous cows led to increased adverse health events (culling rate, retained fetal membranes, puerperal metritis, clinical ketosis, left displaced abomasum) relative to Norm cows.  Multiparous cows with HKHG had fewer metabolic disturbances (hypomagnesemia, hypocalcemia, elevated NEFA) than HK cows. Cows with HKHG had an increased incidence of clinical ketosis and left displaced abomasum relative to Norm cows.  Cows with HG had similar metabolic profiles to Norm cows and had lower incidence of retained fetal membranes and puerperal metritis than cows with HK. Multiparous cows with HG produced more milk than Norm cows from wk 10 to 20  Multiparous cows with HK produced less milk than Norm cows. For primiparous cows, HK did not have a negative effect on milk production compared with Norm cows

Answer 46

 Treatment in HG cows decreased clinical ketosis, increased milk production in the fifth week of lactation for multiparous cows, and tended to increase 305-d mature-equivalent milk yield (305ME) for primiparous cows compared with untreated cows with the same metabolic profile.  For cows with HKHG, treatment increased 305ME in multiparous cows and tended to increase 305ME in primiparous cows.  No differences were found for treatment among any of the metabolic groups regarding reproductive outcomes, nor were any treatment effects found among HK cows. Glycemic status may help identify metabolically challenged early postpartum dairy cows, which may have differential response to PG and B12 treatment

Answer 47

 The final multivariable linear regression model indicated that farms that fed transition milk had fewer than half the number of antimicrobial treatments per calf-year than those who did not feed transition milk.  The number of antimicrobial treatments per calf-year in preweaning calves was low on many farms, and there was low use of highly important drugs for human medicine

Answer 48

 Prepartum serum NEFA concentrations were associated with diseases diagnosed during the first 30 d in milk (DIM) and culling within the first 50 DIM.  The optimal NEFA threshold associated with diseases was ≥290 µmol/L for retained placenta, ≥300 µmol/L for metritis and abomasal displacement, and ≥280 µmol/L for clinical mastitis and hyperketonemia. The level associated with the occurrence of at least one of these diseases in the first 30 DIM was ≥280 µmol/L, but it was ≥260 µmol/L for culling in the first 50 DIM.  our results demonstrate a relationship between NEFA concentrations in the 14-d period before calving and the subsequent development of diseases and culling. Prepartum NEFA concentrations thresholds between ≥260 and 300 µmol/L appear to be a strategic choice. However, considering the low accuracy, their use at the cow level should be performed with caution.

Answer 49

 The results showed that the mean mild cold stress durations were 605.3 h (25.22 d) and 725.5 h (30.23 d) and the moderate cold stress durations were 67.2 h (2.8 d) and 96 h (4.0 d) on the south and north sides of the barns, respectively.  Simultaneously, generalized linear mixed model showed that there were significant correlations between the daily cold stress duration and milk yield, feeding time, lying time, and active steps in the cows on both sides. This method can reasonably indicate cow cold stress conditions and better guide cold protection practices in actual production. This method can reasonably indicate cow cold stress conditions and better guide cold protection practices in actual production.

Answer 50

* SCP supplementation increased the ruminal SCFA concentration, ruminal papilla height, and fiber digestibility, pointing toward stimulation of the development of the rumen in calves. * SCP supplementation increased the serum concentrations of total protein, IgA, and IgG but decreased fecal pathogen colony counts, suggesting that SCP could help calves to promote immunity and resistance to pathogens. * SCP increased average daily gain and dry matter intake preweaning but not postweaning suggesting that SCP is better supplemented to preweaning calves to achieve the best results. * Based on the dose-response curve, 24 to 25 g/d might be the optimal dose range of SCP supplementation (into starter feed) preweaning to achieve the best overall effect. * Overall, SCP supplementation improved growth performance, rumen development, and immunocompetence in calves, particularly in preweaning calves.

Answer 51

* Methane emission intensity was lowest with ES-VL+ diets compared with LS-VL− diets (−30%; 17.1 vs. 24.5 mg/kg of energy-corrected milk). * Immature grass and vine leaf addition each caused about half of the respective declines. * Cows consuming any of the ES diets and the LS-VL+ diet consumed and excreted (urinary N) significantly more N than those consuming LS diets. However, when related to N intake, no differences were recorded. * Unexpectedly, vine leaves did not mitigate urine N excretion. * Our results demonstrate that feeding immature herbage in combination with vine leaves reduces methane yield; however, the associated high urinary N losses need to be addressed.

Answer 52

* Positive associations existed between total ruminal protozoa (TRP) and isotrichids with CH4 emissions but not between entodiniomorphids and CH4 emissions. * Both TRP and isotrichid models can accurately predict CH4 emissions across different ruminant types . * Isotrichid CH4 prediction model was more robust than the TRP. * Our results confirm that isotrichids are more important than entodiniomorphids in methanogenesis. Distinguishing these 2 populations yielded a more robust CH4 prediction model than combining them as total protozoa.

Answer 53

The integrated results indicated participants had a dual vision of the cow, seeing her as both domestic and wild. A scenario with housing in winter and grazing in summer therefore suited her, providing both protection and naturalness, and was most associated with analytic thinking. Interviewees also confessed ignorance about the cow's needs, either deferring to others' judgment-including the cow herself-or using familiarity and anthropomorphism to assess the scenarios. This again resulted in most optimism, confidence, and positivity for housing in winter and grazing in summer, and most negativity for housing cows year-round. Grazing was aspirational, but keeping cows outside in winter was confusing and concerning. These findings offer opportunities for the dairy industry to adapt communication or systems to better meet societal views; for example, incorporating access to pasture or increasing cow choice.

Answer 54

* We found no differences in daily milk yield between end-of-milking criteria * However, fat yield was compromised when the percentage of the herd with a truncated milking exceeded an estimated 33% at a milking session, which occurred in the TAD 8-16 herd due to the divergence from the average milking interval * Applying a fixed milking time had no detrimental effects on udder health, except in the OAD herd in mid-late lactation, which had both a higher cell count and new intramammary infection rate. * Consequently, we conclude that, in general, with appropriate monitoring (e.g., weekly inspection) to ensure the proportion of the herd with truncated milkings does not exceed 33%, farmers in pasture-based dairy systems can use a fixed milking time to improve parlor efficiency.

Answer 55

* Results showed that parity had the most significant effect on the scale (parameter a), the rate of decay (parameter c), and the 305-d milk yield. * The month of calving had the largest effect on the rate of increase (parameter b) for models fit with data from all lactations. * The calving month had the most significant effect on all lactation curve parameters for first lactation models. However, age at first calving, year, and milking frequency accounted for a higher proportion of the variance than month for first lactation 305-d milk yield. * All parameter estimates and 305-d milk yield increased as parity increased; parameter a and 305-d milk yield rose, and parameters b and c decreased as year and milking frequency increased. * Calving month estimates scale, rate of deacy and rate of increas, and 305-d milk yield were the lowest values for September, May, June, and July, respectively. The results also indicated the random effects of herd and cow improved model fit. Lactation curve parameter estimates from the mixed-model analysis of individual lactation curve fits describe well US Holstein lactation curves according to temporal, spatial, and management factors.

Answer 56

* Given that linear type traits are frequently scored in first parity and are genetically correlated with survival in older parities, they may be suitable early predictors of survival, especially for later parity cows. Additionally, the direction of the genetic correlations between survival and rear udder height, teat length, and udder depth did not change between parities; hence, selection for survival in older parities using these linear type traits should not hinder genetic improvement for survival in younger parities.

Answer 57

* We conclude that measures of feeding behavior could be useful indicators of dairy cow feed efficiency, and individual cows that eat at a slower rate may be more feed efficient.

Answer 58

* The results showed that adding breeding goal weight to resilience indicators, such as body condition score and daily deviation from the lactation curve (LnVAR), could reverse the negative trend observed for resilience indicators. * We observed higher genetic gain in beef production, fertility, and udder health when breeding for more resilience, but from an economical point of view, this was not high enough to compensate for the reduction in genetic gain in milk production.

Answer 59

Uninfected secretion samples had 133.2 [95% confidence interval (CI): 16.8 to >999.9] times greater odds to be thick compared with samples infected with a major pathogen, and 14.4 (95% CI: 8.5 to 24.1) times greater odds to be thick compared with samples infected with non-aureus staphylococci (NAS). * These results indicate that mammary secretion viscosity (thicker) and SCC measurement (higher) may be useful tools in identifying primigravid heifer quarters with IMI.

Answer 60

* Bacterial diversity differed significantly between HF and BB samples. * In HF the bacterial composition of colostrum leading to low serum IgG levels in the calf differed from that of colostrum leading to high serum IgG levels. Results of the present study indicate that the microbes present in colostrum are associated with transfer of passive immunity in neonatal calves.

Answer 61

* Treatment consisted of 2 formulations of a multistrain bacterial-based probiotic added in colostrum (PBF1) and milk (PBF2). Treatment calves received 2 g of PBF1 added to each colostrum feeding, and 1 g of PBF2 added to the milk at the morning feeding 3 times per week up to weaning * In conclusion, the probiotic program did not affect the incidence of enteric disease or the growth of preweaning heifer calves.

Answer 62

* A total of 56% of calves retained their navel cord remnant beyond the end of the observation period, and calves began to shed their navel cord remnants as early as d 2. * In addition, at least once during the observation period, 85% of calves had a proximal navel diameter measurement over a 13-mm threshold recently proposed to identify navel infections. * For distal navel diameter measurements, 72% of calves had a diameter over the 13-mm threshold at least once during the observation period. * No associations were identified between navel healing outcomes and dam, calving, and calf factors. * Navel measurement outcomes were associated with calving and calf factors. Specifically, proximal navel stump diameter was associated with the day of observation (decreased from d 5 to 14), calf sex (smaller in female calves), time of birth (larger in calves born overnight or unobserved, compared with the morning), and birth weight (larger in birth weights >44.1 kg compared with <38.5 kg). * The wide range in time to navel cord remnant drying and drop-off suggest that these measures may not be adequate indicators of calf age on their own.

Answer 63

* No apparent differences were detected in the hazard rate for time to first lame event between heifers in the 2 treatment groups. No associations were identified between heifers in the 2 groups for any of the secondary outcome measures (milk solid production, change in body condition score during early lactation, time from onset of breeding season until conception, feasibility of the regimen and change in sole soft tissue thickness and profile).

Answer 64

* We concluded that the urine testing is a more sensitive predictor of blood BHB concentration than the milk testing. The UT and MT tests diagnosed ketotic cows approximately 2 d later than the BT. The possible consequences of delay in detection of ketosis in milk and urine should be investigated.

Answer 65

* Using LAME1 (one timepoint), 69.2% of cows were considered lame at some point during the trial, with an average point prevalence of 31.8% (SD: 2.8) and average incidence rate of 10.9 cases/100 cow weeks (SD: 3.7). Lameness prevalence decreased to 28.0% when using LAME5 (5 consecutive scoring events). * We conclude that lameness prevalence estimates are dependent upon case definition and that the use of more stringent case definitions results in fewer cows classified as lame. * These results suggest that routine locomotion assessments be conducted at least every 2 wk, and that cows should be defined as lame on the basis of 2 consecutive assessments

Answer 66

* This study suggests that feeding MCFA to calves affects the energy status (lower NEFA) of calves around weaning and vaccinating dairy calves with ovalbumin combined with an aluminum hydroxide adjuvant is an effective way to evaluate the adaptive immune responses.

Answer 67

* The sensitivity (Se; 95% credible interval) and specificity (Sp) for o WISC were 77.9% (64.8-90.2) and 81.9% (76.3-88.2). o CALIF, the Se was 67.1% (53.6-80.1) and Sp 79.1% (73.9-84.6). o TUS Se was 59.8% (46.5-73.1) and Sp was 84.8% (80.0-89.5), o AUSC, Se was 58.8% (41.3-79.8) and Sp was 98.6% (95.7-99.9). o Se and Sp of HAP was 67.6% (55.3-78.8) and 46.7% (41.4-52.2), respectively. * The performance of the scoring systems was similar to, or better than, the performance found in North American studies, despite the fact that calves were in a tropical environment.

Answer 68

* Larger herds had higher odds of detectable antibodies in BTM (herd size >120 cows, odds ratio = 8.8). * An association was also found between antibodies in BTM and both a higher late calf mortality (2–6 mo) and a higher young stock mortality (6–15 mo). * We do not recommend using PCR on BTM to detect infected herds, owing to the low detection frequency in this study

Answer 69

* In conclusion, feeding RPL pre- and postpartum improved indicators of uterine immune status (downregulates the expression of TLR4, SLC7A6, EHMT2; upregulates the expression of APOL3 and NFKB1), but did not change days to first ovulation postpartum.

Answer 70

* We conclude that exposure to a heat-stress environment increases total-tract gastrointestinal permeability. This study highlights important mechanisms that might account for milk production losses caused by heat stress, independent of changes in DMI. Our observations also suggest that dietary supplementation of OA/PB is a mean to partly restore ECM production and improve nitrogen efficiency in dairy cattle experiencing heat stress.

Answer 71

During the first 4 wk of the dry period, all cows were fed a controlled-energy, high-fiber diet (CE) as a total mixed ration for ad libitum intake. During the last 3 wk before calving, half of the cows were switched to a higher-energy, close-up diet until calving (CU), whereas the other half continued to receive the CE diet. Within each dietary group, half of the cows received monensin (MON) * Cows on the CE + CON diet had a greater ruminal proportion of acetate than did cows fed CU + CON, whereas cows fed monensin on either diet were intermediate (diet × monensin interaction). Addition of MON to the CU diet decreased the proportion of propionate (diet × monensin interaction). higher content of straw in the controlled-energy diet increased mass of rumen contents prepartum, but did not affect rumen papillae length. * Monensin inclusion differentially affected liquid passage rate and VFA proportions depending on the diet to which it was added.

Answer 72

* The changes in DMI were related to changes in leaf to stem ratio, fiber concentration, and organic matter digestibility determined in vitro in samples of the fresh grass harvested throughout the experiment. We detected no differences in milk or ECM yield between silage with concentrate and late harvested fresh grass with concentrate The study implies that feeding silage instead of fresh grass has no effect on DMI, ECM yield, or CH4 yield, and that concentrate supplementation can increase milk production, affects milk quality, and reduces the effect on climate, whereas feeding less mature grass increases DMI and milk yield, but has no effect on CH4 yield.

Answer 73

* There was a positive linear association between RFI and DMI in multiparous cows and a positive quadratic relationship in primiparous cows, where the rate of increase in DMI was less at higher RFI. Eating rate, DMI per meal, and size of the largest daily meal were positively associated with RFI. * Daily temporal analysis of FB revealed an interaction between RFI and time for eating rate in multiparous and primiparous cows. * The eating rate increased with greater RFI at 11 of 12 time points throughout the day, and eating rate differed across RFI between multiple time points. * There tended to be an interaction between RFI and time for eating time and bin visits in multiparous cows but not primiparous cows. * Overall, there was a time effect for all FB variables, where DMI, eating time and rate, and bin visits were greatest after the initial daily feeding at 1200 h, increased slightly after each milking, and reached a nadir at 0600 h (6 h before feeding). Considering the relationship between RFI and eating rate, additional efforts to determine cost-effective methods of quantifying eating rate in group-housed dairy cows is warranted.

Answer 74

* Although preliminary, these results are encouraging because size and position score seems to be more heritable than and strongly genetically correlated with number of services, nonreturn rate, and first service to conception, indicating potential for effective indirect selection response on these traits from SPS genetic selection. The SPS showed null correlations with production traits

Answer 75

* Genetic analysis of digital cushion thickness indicated that it is heritable and has a negative genetic correlation with the severity of sole lesions.

Answer 76

* Our results demonstrated that dairy cows could experience periods of short or no lying time during inclement weather and muddy paddock soil conditions. * Lying time decreased when paddock soil conditions became very wet and muddy, especially after rainfall. * In these conditions, an alternative drier lying area should be offered to improve animal welfare.

Answer 77

* Pair housing reduced calves’ interactions with items compared with individual housing. Individually and pair-housed calves’ frequencies of overall interaction with items varied with time of day, with frequencies increasing to peaks at 0700, 1500, and 1900 h. * In conclusion, dairy calves are likely to prefer a fixed multi-item enrichment presentation schedule over a rotating schedule with a single enrichment item presented at one time. * The items were likely more important for individually housed calves because those calves showed more interactions with them than did pair-housed calves. * The items should not be changed or cleaned around feeding times because dairy calves showed more interactions with the items at both times.

Answer 78

* Mycobacterium avium subspecies paratuberculosis-infected cows were more likely to be detected if tested within 2 weeks after SICCTT. * The SICCTT test had a delayed effect on noninfected cows, with higher false positive risk 2 to 4 weeks after SICCTT. To avoid interference, evaluating the milk ELISA more than 30 days post SICCT is most appropriate.

Answer 79

* The participants reported observing behavioral changes of cows such as increased vocalizations and decreased lying time associated with dry-off. * Selective dry cow therapy was applied on 74% of the farms, and 44% of the participants indicated the use of antibiotics at dry-off as being “rather often,” “often,” or “always.” * We found that farmers showed an interest in testing the presented drying-off approach of incomplete milking. * In addition, the farmers indicated that they would be more willing to test incomplete milking before dry-off if it became available for automated use in milking parlors or robots. * Uncertainties regarding udder health appeared to be the main barrier for the adoption potential of this approach.

Answer 80

* Meta-analysis results showed higher odds for mortality (n = 8 studies) and diarrhea (n = 7 studies) in calves with inadequate transfer of passive immunity compared with those with adequate immunity

Answer 81

* During preweaning human approach tests in the home pen, individually housed calves had shorter latencies to contact the human (22.4 vs. 45.1 s; individual vs. pair housing) and spent more time in contact with the human [80.5 vs. 41.1 s; standard error (SE) = 9.9; individual vs. pair housing], with similar responses between repeated tests. * In the arena approach test, individually housed calves spent more time oriented toward the human (134.6 vs. 81.3 s; SE = 16.5; individual vs. pair housing), whereas pair-housed calves were more likely to perform pen-directed non-nutritive oral behavior (60 vs. 40% of calves; pair vs. individual housing), suggesting differences in interest directed toward the human compared with the novel environment. Effects of treatment persisted during the postweaning group pen approach test, with previously individually housed calves tending to spend more time looking toward the human (53.0 vs. 30.0 s; SE = 9.4; individual vs. pair housing) and more likely to contact the human (47 vs. 12% of calves; individual vs. pair housing). * We demonstrated carry-over effects of calf social housing on human-directed behavior immediately postweaning, suggesting that early life social contact may influence development of human-animal relationships.

Answer 82

* Except for a few outcomes for which no difference was observed, cows detected in estrus during the VWP had better performance than cows not detected in estrus. * We conclude that a targeted reproductive management program designed to prioritize AI at estrus detection by grouping cows based on detection of estrus during the VWP was an effective strategy to submit cows for first service resulting in similar or improved performance than a non-TRM program that prioritized AIE or an all-TAI program with extended VWP. * Also, automated estrus alerts recorded during the VWP might be used as a strategy for identifying subgroups of cows with different reproductive performance.

Answer 83

* Our findings suggest that dietary supplementation of 2 g/d of algae β-glucans to milk replacer improved fecal status and may affect growth, as evidenced by a higher weaning weight, compared with control calves. Future studies should explore the effect of algae β-glucans on lower-gut physiology and digestibility in dairy calves.

Answer 84

* These data suggest that the negative effects of feeding distillers grains on production of lactating cows can be partly explained by a decrease in nutrient digestibility (milk yield) and excessive anion load (milk fat). * The milk fat response to DG-DCAD suggests that milk fat depression observed with a diet with high content of distillers grains can be partially alleviated by supplementation of cations. * In the current study, we observed no beneficial effects of DG containing yeast bodies

Answer 85

* Inclusion of the PFA pellet at 10% with a calf starter improved BW, solid feed, and energy intake after weaning. However, these benefits were conditioned by fat source and its digestibility.

Answer 86

* Organic dairy clients were typically a small fraction of the overall workload for local veterinarians, which precluded their ability to accumulate experience. In contrast, a handful of specialized veterinarians in the organic milk processing industry work more frequently with organic producers and have published most of the available resource materials on organic dairy herd health.

Answer 87

* In conclusion, greater proportions of short-AGD cows commenced estrous activity by 50 DIM, had larger preovulatory follicles, exhibited greater duration of estrus, had reduced progesterone concentration at estrus, had greater ovulation rates and progesterone concentration 7 d after estrus compared with long-AGD cows, with no difference in CL size between AGD groups.

Answer 88

* Cows fed the CMA diet had higher dry matter intake in both the prepartum (+1.08 kg) and postpartum (+0.94 kg) periods compared with cows fed the CON diet. * Fat yield (+0.11 kg), fat concentration (+0.43%), and 4% fat-corrected milk (+1.56 kg) were higher in cows fed CMA than in cows fed CON. * The concentration of plasma serum amyloid A was reduced and that of serum P was increased on the CMA treatment compared with the CON treatment. * These findings demonstrate the benefits of supplementing CMA to dairy cows during the transition period compared with a CON treatment containing limestone as the primary Ca source.

Answer 89

* Calves receiving FSP and OLP had greater average daily gain, BW gain, skeletal gain (withers height or heart girth, respectively), and feed efficiency compared with CON animals with no difference between FSP and OLP. * the chance of BRD being lower in FSP- (but not OLP-) supplemented versus CON animals * Supplementing FSP or OLP decreased the duration of diarrhea and BRD but not their frequency compared with CON. Duration of diarrhea was not different between FSP- or OLP-supplemented calves but calves supplemented with FSP had shorter days with BRD compared with OLP-supplemented calves. Supplementation of the liquid feed with FSP or OLP, especially FSP, had beneficial effects on calf growth performance and health. Further experiments are warranted for optimizing the dosage and duration of feeding FSP or OLP as feed additives for dairy calves.

Answer 90

* This suggests that milk intakes were regulated by the energy density of the milk supplied. * The percentage of calves requiring therapeutic interventions related to diarrhea was greater in WP-fed calves (29%) than high fat and high lactosee calves (4%), whereas high protein (13%) did not differ with other groups. * Calves fed HF had greater serum nonesterified fatty acids compared with other groups, and greater serum amyloid A compared with WP and HL calves. Although growth differences were limited among MR groups, the metabolic profile largely differed and these differences require further investigation.

Answer 91

* Milk yield was not affected by treatment in multiparous cows (44.1 vs. 44.2 kg/d); however, primiparous cows supplemented with OTM had lesser yields than primiparous cows supplemented with STM (31.9 vs. 29.8 kg/d). * In conclusion, complete replacement of STM by OTM caused modest changes in rumen fermentation, feeding behavior, energy metabolism, and performance of dairy cows, improving postpartum DMI in multiparous cows and reducing circulating levels of nonesterified fatty acids.

Answer 92

* Higher SPS calves showed an increase in rumen pH magnitude (1.46 ± 0.07) compared with low SPS calves (1.16 ± 0.07), a decrease in rumen pH in wk 8 (high SPS: 5.37 ± 0.12; low SPS: 5.57 ± 0.12), and a decrease in haptoglobin in wk 8 (high SPS: 0.24 ± 0.06 g/L; low SPS: 0.49 ± 0.06 g/L). * The majority of differences came from increased starter intake in general, which suggests that with completely pelleted starters the differences in starch and NDF do not elicit drastic changes in fermentation, subsequent end products, and any resulting inflammation in calves around weaning.

Answer 93

. Although extensive research exists on pain control practices for disbudding, this review identified further gaps in knowledge and areas for future research. Mechanical nociceptive threshold can be evaluated around the disbudding wounds and is a reliable test in older calves; however, this outcome in very young calves after caustic paste disbudding has been reported to be inconclusive compared with that in older calves. As well, research evaluating xylazine sedation for disbudding has reported both potentially positive and negative results that are difficult to interpret or base suggestions on for the use of this drug. Finally, wounds caused by disbudding take a long time to heal (up to 13 wk) and have increased sensitivity for the entire healing process

Answer 94

The veterinarians' skills in communication and relation building were considered especially important. Some farmers were perceived as having little interest in, or lacking deeper knowledge about, VHHM services. The promotion of VHHM services was mentioned as an important factor to increase farmer demand. Participants described VHHM as work demanding high skills and continuous capacity development. Veterinarians' personal commitment and motivation were also described as important for the extent to which VHHM services were performed. . Lack of time was a major barrier for VHHM. On-call duty time and subsequent compensatory leave affected the total time available, and participants described time conflicts between VHHM and emergency services; moreover, it was perceived as challenging to find sufficient time for capacity development in several different species for veterinarians working in mixed practice.

Answer 95

 According to these findings, predictions of plasma NEFA and milk FA based on milk MIR spectra of routine test-day samples and the frequent measurement of milk BHB by Herd Navigator gave equally good predictions of cow ES during the first weeks of lactation. Our results indicate that routinely measured milk traits can be used for ES evaluation in early lactation.

Answer 96

 These results suggest that lame dairy cows will use pasture when provided with free-choice access, primarily at night, and that access to pasture aids in lameness recovery.

Answer 97

 In conclusion, a short stay in the close-up group should be avoided to improve milk yield at first test day and to minimize culling risk for parous cows. A long stay in the close-up group (>30 d) was associated with reduced milk production and an increased ratio of fat and protein in milk of parous cows and increased SCS of nulliparous and parous cows.

Answer 98

 Conclusion. veterinarians are concerned about the care of surplus calves on dairy farms and believe that they have an important role in developing solutions together with their farmer clientele.

Answer 99

 pH patterns, rather than time pH <6, were associated with metabolic health and feed intake: high variation in daily pH was reflected in higher blood concentrations of nonesterified fatty acids.  pH deviations of the harmonic model were negatively associated with feed intake and rumination behavior  Conclusion: confirms the biological importance of pH metrics focusing on pH variation and pH deviations and provides deeper insight into its associations with metabolic health status, feed intake, and activity during early lactation.

Answer 100

 Adaptation to daily temperature and THI was already noticeable from a mean temperature of 12°C or a mean THI of 56 or above, when dairy cows started spending less time lying and eating and spent more time standing. Further, rumination time decreased, although only in dry cows and cows on AMS farms.  With higher values for daily mean THI and temperature, walking time decreased as well. These patterns were very similar for temperature and THI variables.

Answer 101

 The study found a calming effect of a trained demonstrator on test cows' heart rate but not on latency to resume feeding or behavioral reaction.  Post hoc analyses revealed a carryover effect on latency, indicating that test cows who were accompanied by an untrained demonstrator first had longer latencies than cows in all other sub-treatments. Adding a calm, experienced cow to groups of dairy cattle may mitigate fear and thereby improve welfare and safety.

Answer 102

 Parity and chronically delayed milk ejection were associated such that compared with cows in their third or greater lactation, the odds (95% confidence intervals, 95% CI) of CDME were 1.27 (0.71–2.25) for cows in their first and 4.77 (2.47–9.22) for animals in their second lactation.  The odds of CDME increased with increasing stage of lactation, with an odds ratio of 0.20 (0.11–0.36) for early and 0.28 (0.15–0.52) for mid-lactation animals, respectively, compared with late lactation cows.  A lameness event during the study period increased the odds of CDME [odds ratio (95% CI): 8.04 (1.20–53.83)], as did a vaccination event 1 wk before the study period [odds ratio (95% CI): 4.07 (0.99–16.71)].  This study confirmed associations between CDME and previously reported risk factors and identified several previously less rigorously investigated health and management events that could be associated with CDME. Incremental milk flow rates from individual cows serve as an automated tool to evaluate milk flow dynamics. This information could be used to improve individual premilking udder preparation to meet the animal's physiological requirements, improve teat and udder health, and enhance parlor efficiency.

Answer 103

 In both nulliparous and primiparous cows, the conception rate of crossbreeding using Japanese Black (JB) semen was significantly higher than that for purebred Holstein breeding.  The conception rate using sexed semen decreased in the warmer months only in nulliparous cows.  Moreover, we grouped primiparous cows according to milk yield during peak lactation (PY; < 25, 25–30, 30–35, ≥35 kg) and the interval from calving to first insemination (CFI; < 60, 60–79, 80–99, ≥100 d), and evaluated their combined effect on the conception rate.  Both PY and CFI strongly affected the conception rate in primiparous cows, which decreased with an increase in PY, even for the group with CFI ≥100 d; however, the conception rate increased for a CFI ≥60 d regardless of PY.  Taken together, this study demonstrates the long-term effect of PY and an independent effect of CFI on the conception rate of cows.

Answer 104

 The Doppler US color mode showed similar accuracy and a higher negative predictive value than the genes selected as biomarkers.  The additional B-mode ultrasound evaluation of the uterine stratum vasculare and the endometrium thickness improved the diagnostic accuracy.  Therefore, assessing the CL-BP by Doppler US allowed early detection of nonpregnant cows at 19 to 20 d post-AI.  The combination of early CL-BP by Doppler US (d 19 to 20) with early embryo detection by B-mode US (d 33–34) could be used to facilitate earlier rebreeding of dairy cows.

Answer 105

 Estimated median Se and Sp of the PAG ELISA test conducted between 23 and 27 d after AI were 0.98 (95% credible interval 0.93 to 1.0) and 0.98 (0.89 to 1.0), respectively, when using a standardized corrected optical density threshold of 0.15.  Although the accuracy of the test under investigation was excellent, more data will be needed to confirm the optimal diagnostic cut point for PAG in milk for early pregnancy diagnosis in this time window.  The optimal timing of pregnancy diagnosis will depend on herd-specific logistics and the action to be taken to re-inseminate nonpregnant cows.

Answer 106

 We conclude that feeding TM for 4 d following an initial feeding of colostrum stimulates villus, mucosal, and submucosal development in all sections of the small intestine in the first few days of life and improves health and growth.

Answer 107

 Exposure to elevated PM2.5 from wildfire smoke resulted in lower milk yield during exposure and for 7 d after last exposure and higher blood CO2 concentration, which persisted for 1 d following exposure.  Effects of PM2.5 and THI on metabolism were contingent on day of exposure. On lag d 0, blood urea nitrogen (BUN) was reduced with higher combined THI and PM2.5, but on subsequent lag days, THI and PM2.5 had a positive interaction on BUN.  Conversely, THI and PM2.5 had a positive interacting effect on nonesterified fatty acids (NEFA) on lag d 0 but subsequently caused a reduction in circulating NEFA concentration. Our results suggest that exposure to high wildfire-derived PM2.5, alone or in concert with elevated THI, alters systemic metabolism, milk production, and the innate immune system.

Answer 108

 The results showed that skin Sensible Heat Loss (SHL) decreased with increasing ambient T and the decreasing rate was not affected by RH or AV.  The average skin SHL, however, was higher under medium and high AV levels, whereas it was similar under different RH levels.  The skin Latent Heat Loss (LHL) increased with increasing ambient T. There was no effect of RH on the increasing rate of LHL with ambient T. A larger increasing rate of skin LHL with ambient T was observed at high AV level.  When ambient T was below 20°C the total LHL (skin + respiration) represented approx. 50% of total heat loss, whereas above 28°C the LHL accounted for more than 70% of the total heat loss. Respiration heat loss increased by 34 and 24% under short and long exposures when ambient T rose from 16 to 32°C.

Answer 109

 Milk and total solid yields were greater by 13.5 and 13.9%, respectively, for B8-/B9B12+ [45.5 (standard error, SE: 1.8) and 5.81 (0.22) kg/d, respectively] compared with B8-/B9B12- [40.1 (1.9) and 5.10 (0.23) kg/d, respectively], but these effects were suppressed when combined with the B8 supplement.   Cows in the B8-/B9B12+ group also mobilized more body fat reserves, as suggested by a tendency to increased plasma NEFA and more milk total solids compared with B8-/B9B12- cows. In summary, our results showed that, under the current experimental conditions, increasing B8 supply did not improve responses to the B9 and B12 supplementation.

Answer 110

 Even though body condition score was not affected by treatment, B8-/B9B12+ cows had greater BW loss by 24 kg, suggesting higher mobilization of body reserves.  Moreover, postpartum dry matter intake for B8+ cows tended to be lower by 1.6 kg/d.  These results could indicate ruminal perturbation caused by the B8 supplement, which was not protected from rumen degradation.  Under the conditions of the current study, in contrast to B8+/B9B12- cows, B8-/B9B12+ cows produced more milk without increasing dry matter intake, although these cows had greater body fat mobilization in early lactation as suggested by the FA profile and BW loss.

Answer 111

 Specifically, predicted liver TAG was inversely related to BCS, whereas PVD and LD increased with increasing heart girth, BCS, and predicted BW.  Generally, no relevant associations were observed between the US parameters and milk production traits, including when expressed in terms of productivity.  In conclusion, this study suggests that US measures of liver dimensions of clinically healthy cows are related to their size, whereas pTAG concentrations reflect body condition status, with no particular implications for milk production and productivity.

Answer 112

* Taken together, under the conditions of this study, elevated MP supply in close-up diets reduced milk production without affecting blood metabolites in multiparous dairy cows during early lactation. A combination of a shorter dry period and increased prepartum MP supply (i.e., SDHP vs. LPLP) improved prepartum dry matter intake without modifying energy-corrected milk yield and blood biomarkers in early lactation cows

Answer 113

* The number of lymphocytes was greater at d 7 in the blood of NCG cows. * The plasma level of malondialdehyde was lower in the NCG group, and blood reactive oxygen species were lower at d 7, whereas total antioxidant capacity tended to be greater in the NCG group and glutathione peroxidase tended to be higher at d 21 in cows fed NCG, suggesting that NCG supplementation improved antioxidation in cows. * The concentration of serum amyloid A was lower in NCG-fed animals during the postpartum stage. * Overall, our results indicated that supplementation with NCG during the transition period showed the beneficial effects on animal health, by improving PMN functions and alleviating inflammation status and oxidative stress in dairy cows.

Answer 114

* Feeding 25(OH)D3 increased colostrum yield. * The plasmatic concentration of 25-hydroxyvitamin D3 was increased with 25(OH)D3 supplementation. 25-Hydroxyvitamin D3 supplementation increased plasma glucose concentration at parturition. * The postpartum dry matter intake was not influenced by treatments. * Feeding 25(OH)D3 increases milk yield, 3.5% fat-corrected milk, and energy-corrected milk and improves milk yield components in early lactation. Overall, these findings suggest that 25(OH)D3 at 3 mg/d can improve the energy metabolism and lactation performance, compared with the current-feeding practice of supplementing vitamin D3 at 0.625 mg/d.

Answer 115

* We identified 5 broad and often interrelated themes evoked by farmers regarding 6-wk CR: o the "good" farmer; o support networks; o free time and family time; o simplicity of a structured system; and o profitability and monetary gain. * The findings of this study identify complexities and challenges at farm level when it comes to increasing 6-wk CR, such as increased workload and challenges associated with large numbers of male calves born during a condensed calving season. * Benefits experienced by farmers as a result of increasing 6-wk CR included increased days in milk and consequently improved cash flow as well as increased grass utilization.

Answer 116

* Milking was the most time-consuming task, representing 31% of farm labor input making it an important focus for potential improvements in efficiency. * The next 5 most time-consuming tasks were calf care (14%), grassland management (13%), cow care (10%), repairs and maintenance (10%), and administration/business (8%).

Answer 117

* The only trait definition that had an estimated genetic variance larger than the standard error was Cyto5(PMN>5%), with an estimated heritability of 0.04. For all other definitions, the genetic variance was not significantly different from zero. * the current study indicates that SCE is heritable at a similar level to that of clinical endometritis and metritis, and has potential as a future fertility phenotype to be used for breeding purposes.

Answer 118

participants in the groups in which the calf was slaughtered after 12 mo of age often specifically linked their acceptance of the practice to the fact that the calves’ lives had a purpose In contrast, only 3% of the participants regarded a slaughter age of <1 mo as appropriate. Besides the 2 main factors (age at slaughter and cow-calf separation), information on pasture access, the healthiness of the meat from the calves, and the exact age of slaughter were also considered important by participants to make a more informed decision about their view on surplus calf management

Answer 119

 M. bovis IFN- ELISpot assay we established could detect infected cattle earlier than the BOVIGAM ELISA test.

Answer 120

 A low concentration (0.6 mM) of FFA can induce oxidative stress and activate autophagy in BMEC. At higher concentrations of FFA (1.2 mM), autophagy is impaired and oxidative stress is aggravated. Autophagy is a mechanism for BMEC to counteract FFA-induced stress.

Answer 121

 The lameness effect size we identified was large and indicated that treating a cohort of animals with the group 3 protocol (therapeutic trim with 3d ketoprofen at treatment and calving), would lead to an absolute reduction in population lameness prevalence of approximately 10% and severe lameness prevalence of 3%, compared with animals treated in accordance with conventional best practice (group 1(therapeutic trim)).

Answer 122

 Cows > fearful of humans had < lying time compared with cows that scored low on this trait.  Cows > calm (during restraint) and investigative (toward the novel object) had > grazing time, which likely contributed to their greater milk production compared with cows that scored low on this trait.  Cows that were more reactive to milking produced less milk than cows that scored low on this trait.  Conclusion: individual differences in daily behavior patterns and milk production of dairy cattle are associated with personality traits of cows, measured using several short behavioral tests.

Answer 123

 Conclusion: there is the potential to use feeding and activity behaviors to identify BRD development in preweaning calves.  We suggest relative changes in unrewarded visits may be useful for algorithm development when d -5 is used as a baseline.

Answer 124

 Conclusion: administering a single application of 7% iodine tincture dip to the umbilicus around the time of birth may not be effective for preventing external umbilical infections. Farm-level management factors, including colostrum management, appear to have more influence on risk of this disease.

Answer 125

 Individual risk factors associated with the hazard rate ratio (HR) for time to first suckling event: 1) time to standing (calves who took more than 1.3 h to stand had a longer time from birth to first suckle); 2) age of the dam (compared with calves that were born from dams >7 years of age, calves born to dams that were 2-3 and 4-7 yr of age had a 1.49 and 1.19 HR, respectively, for time from birth to first suckle in the calving paddock).  Farm risk factors associated with the HR of suckling: 1) frequency of calf collection (calves that were born on farms that collected calves once a day suckled earlier than calves on farms that removed calves more than once a day); 2) temperature (a minimum temperature of <10°C within 6 h of a calf being born was associated with a 0.69 hazard of suckling in the calving paddock).  Conclusion: large farm variability.

Answer 126

 As a cross-sectional measurement, diagnostic accuracy of spontaneous cough is too low to be used as a criterion to select animals with pneumonia for antimicrobial treatment.  At the group level, cough monitoring holds potential as an early warning sign, after which lung ultrasonography should follow.

Answer 127

 Despite statistical significance, model accuracy, even if refined with misclassification cost term analysis, was limited at the individual level, showing the limits of using physical signs and BW or their combination as a reliable proxy of age.  The sensitivity of these models to find calves < 9 d old was not to be used for monitoring compliance with the Canadian federal regulation.  The relatively high model specificity may help to use this model as a rule-in test rather than a rule-out test.

Answer 128

 The odds of having SUWL in HYK+ was 0.66 times the odds of that for HYK- cows.  For cows diagnosed with a lesion (digital dermatitis, corkscrew, toe, foot rot, or other lesion) at their precalving hoof trim, the odds of having SUWL for HYK+ cows were 0.43 times the odds of that for HYK- cows.  Conclusion: the wide range of compatible causal estimates suggest that hyperketonemia likely has a limited role in the development of SUWL in cows with or without a hoof lesion precalving.

Answer 129

 Although most of the studies were well-designed and used high-quality data, the systematic approach review does not allow combination of the cost estimates of into a single figure.

Answer 130

 Conclusion: primiparous cows move further away from herd members at calving than multiparous cows and suggest that primiparous cows prefer to isolate themselves through distance rather than seeking artificial cover.  Conclusion 2: contrary to expectation, the hides did not make more cows select a calving site away from the feeding area.

Answer 131

 The colostrum IL-6 concentrations were positively associated with serum IL-6 in the first 3 wk of life.  Colostrum IL-1 was positively associated with calves' serum IL-1 during the first week of life, and colostrum TNF- was positively associated with calves' serum TNF- during the first 2 wk of life.  Serum IL-1 concentrations differed over the 3 wk, being the highest during the first week and the lowest during the second week.  For IL-6, the concentration during the first week was the highest, and for TNF-, a steady decline in the concentration was observed.  Serum SAA concentrations were elevated during the first 2 wk of life and subsequently declined during the third week.  Albumin concentrations were lowest in the first week, whereas Hp concentrations were highest during the second week.  Serum concentrations of SAA, Hp, IL-6, and TNF- during the second week were negatively associated with ADWG at 9 mo of age.  The SAA and Hp concentrations during the third week of age had a negative association with 9-mo ADWG.  Conclusion: colostrum cytokines influence calf serum cytokine concentrations. Thus, they influence the newborn calves' adaptation to the environment and the development of their immune system. Factors that activate an APR during the second and third week of life have a long-term influence on calves' development.

Answer 132

 Conclusion: biological nutritional (no limitation) milk feeding program for calves can result in faster healing times and more activity, and that providing an extra NSAID 3 d after disbudding appears to slow the healing process but may result in less pain experienced by the calf 1 to 2 wk after the procedure.  Conclusion 2: after the complete removal of the horn bud, wounds can take more than 8 weeks to re-epithelize and fully heal.

Answer 133

 Conclusion: use of the on-farm mastitis test kit could enhance sustainable antimicrobial drug use by rapidly identifying Streptococcus mastitis for targeted treatment.  Conclusion2: Staph. aureus outbreak where cows can be rapidly screened to identify cases for segregation or culling during an outbreak and kit-negative cows further confirmed by milk culture or qPCR.

Answer 134

In conclusion, SCC is negatively associated with the risk for conception and with daily milk yield in grazing dairy cows. This negative relationship with conception is higher when SCC increase occurs after the service date and it is influenced by severity of mastitis, and in the case of milk yield, the negative association is influenced by parity, milk production quartile, and severity of mastitis.

Answer 135

 Conclusion: staphylococcal and mammaliicoccal species were highly prevalent among samples from both farm types (used>unused).

Answer 136

 For every hour longer postbirth that it took for a calf to have its first suckling event, odds of FPT at d 3 increased by 1.21 times, and compared with calves that only suckled once, calves that suckled 2, 3-5, or >5 times had 0.42, 0.35, and 0.10 times the odds of FPT, respectively.  For every 1-percentage-point increase in the Brix % of the colostrum, the odds of FPT decreased by 33%.  Calves that suckled in the paddock and were fed colostrum with ≥22% Brix had the highest STP, and lowest odds of FPT, of any suckling/Brix % combination. Calves that suckled in the paddock and were fed colostrum with ≥22% Brix had the highest STP, and lowest odds of FPT, of any suckling/Brix % combination. There was a trend for STP to be greater in calves that suckled in the paddock and fed <22% Brix compared with calves that did not suckle in the paddock and fed ≥22% Brix. However, the calves in the former group also tended to have a greater risk of FPT at d 3, and a greater STP variability. There were very large between-farm variabilities for rates of suckling, colostrum feeding, and FPT risk that urgently require further investigation for calves born at pasture.

Answer 137

Consequently, total DMI was greater on the H-AMS treatment (30.4 vs. 29.1 kg/d). When on the H-AMS treatment, cows who were more alert-curious consumed more PMR, whereas cows who were more fearful of the novel human were less likely to receive the maximum amount of AMS concentrate available, limiting their total DMI and increasing the day-to-day variability of that intake.  data suggest an association between dairy cow personality traits and how cows respond to increased AMS concentrate allowance.

Answer 138

 Relationships exist between eliminative behaviors (frequencies and distribution over time and space for defecations and urinations, how the animal responds to cow-related and environmental factors by way of altered patterns of defecation and urination, and how an animal carries out and responds to its own acts of elimination) and activity levels of the animals and activity levels of the people who manage them, suggesting that types of housing systems play a key role in mainly where and when eliminations occur.  It also seems that individual animals vary in their elimination frequencies, in which case it may be interesting to determine what aspects of their individuality contribute to these differences.  Refining the timing of management routines and training of animals are some options in the next steps toward managing eliminative behaviors.

Answer 139

 Conclusion: although LF calves had a greater AUC, HF calves were still able to absorb IgG in the second and third meal, allowing HF calves to achieve serum IgG levels similar to those of LF calves at 24 h.  Conclusion 2: the provision of 3 meals at 70.5 g/L of IgG within the first 12 h of life did not result in added benefits to serum IgG or AEA levels.

Answer 140

 Cows categorized as very fat had lesser milk yield than other clusters.  Overall, overconditioned cows lost more BFT than normal or lean cows. However, those OC cows with a smaller loss of BFT produced less milk than OC cows with greater losses

Answer 141

 We infer that although selecting cows for short AGD is expected to have an adverse effect on milk yield, the anticipated gain in fertility will outweigh the small decline in milk yield, strengthening the potential of AGD as a novel reproductive phenotype for use in future breeding programs to improve fertility.

Answer 142

 There was an interaction effect between treatment and parity for plasma progesterone; however, plasma progesterone and ISG did not differ between treatments. There were no effects of NGF for P/AI at 37 d post-AI (NGF = 40.0% vs. control = 41.6%), 65 d post-AI (NGF = 36.0% vs. control = 38.1%), and for pregnancy loss (NGF = 8.4% vs. control = 7.7%). The current study revealed that effects to NGF in lactating Holstein cows were minor and contingent with parity for progesterone, and no improvement in ISG relative abundance and P/AI were observed.

Answer 143

 Moving from the current dairy system to the target dairy system was reported to reduce the environmental impact per kilogram of FPCM across all impact categories investigated. When expressed per hectare, transitioning toward the target dairy system reduced acidification, freshwater eutrophication, and nonrenewable energy depletion by 2.0%, 8.8%, and 13.8%, respectively.  In contrast, transitioning toward the target dairy system increased global warming per hectare and, to a lesser degree, marine eutrophication potential per hectare.  The increase in global warming and marine eutrophication potential per hectare was attributed to the increase in stocking rate and subsequently milk production per hectare (9,950 vs. 14,100 kg of FPCM/ha).  This study demonstrates that the adoption of management practices that improve system efficiency will reduce the environmental impact per kilogram of FPCM and can contribute to the future sustainability of pasture-based dairy systems.  However, improved system efficiency can be offset by the associated increase in productivity, highlighting the importance of reporting multiple environmental impact categories and functional units to prevent pollution swapping.

Answer 144

 The proportion of days with diarrhea significantly decreased weight gain at 14, 56, and 77 d following arrival.  An increased proportion of days with diarrhea increased the risk of mortality.  A higher proportion of days with an abnormal fecal score increased the hazard of antibiotic treatment. Our results highlight the substantial influence the presence of abnormal fecal consistency has on short-term weight gain, mortality risk, and morbidity risk. We also demonstrate that diarrhea occurrence can be predicted using body weight at arrival and calf source. Further research should evaluate longer-term effects of diarrhea and better understand the effect of arrival weight on neonatal calf disease risk.

Answer 145

EXP: serial protocol-based clinical and ultrasonographic examinations, puncture of the jugular vein for blood collection or drug application, and liver biopsy samples, 14 d before until 42 d after parturition  Most procedure-related adverse effects were associated with transcutaneous liver biopsies and included diffuse inflammation of the skin incision, abscessation of the skin or subcutis, and increased liver echogenicity of the biopsy site.  The experimental procedures had a negative effect on milk yield at the start and end of lactation resulting in a lower 305-d milk yield in the EXP group than in the CTR group.  The milk fat % and SCC was higher in the EXP group than in the CTR group.  No effect on first service conception rate and time to pregnancy.  Fewer stillbirths in the CTR vs EXP group.  No effect on time to culling or type of culling, whereby poor production was a more frequent reason noted for culling in the EXP group. Experimental procedures had no effect on first service conception rate and time to pregnancy, but had a positive effect on stillbirth rate with fewer stillbirths in the CTR group (0%) than in the EXP group (3.9%). Furthermore, experimental handling had no effect on time to culling or type of culling, whereby poor production was a more frequent reason noted for culling in the EXP group. Procedure-associated impairment of production in dairy cows is rarely reported and allows the estimation of the effects of such a study protocol on animal health and production. As a limitation for the interpretation of the results, the number of animals included and conduction in one single herd have to be considered.

Answer 146

 The prevalence of herds with ≥15% of sampled cows with elevated concentrations of nonesterified fatty acids prepartum and postpartum, β-hydroxybutyrate postpartum, and haptoglobin postpartum was 51%, 51%, 51%, and 57%, respectively.  Cows were moved to a calving pen when showing signs of labor and remain there or in maternity pen for a median (range) time of 2 (0-24) h after parturition.  Primiparous cows remained in the first pen moved to after parturition for a longer period than multiparous cows.  ~ 20% of herds had routine vaccinations administered in the maternity or calving pen, first pen after parturition, or both.  Almost all herds performed fresh cow health checks but only 53% locked up all fresh cows daily.  More herds housed primiparous and multiparous cows in separate pens during the far-off dry and high-lactation periods compared with the close-up dry and fresh periods.  At least half of the pens observed during the far-off dry, close-up dry, and fresh periods had a stocking density <100%. Approximately one-third of pens observed during the far-off dry period had feed pushed up ≤4×/d compared with approximately 15 to 20% of pens observed during the close-up dry, fresh, and high-lactation periods.  More than half of the total mixed ration samples acquired from the far-off and close-up dry period visits had greater than the recommended proportion of particles in the 19-mm screen of the Penn State Particle Separator. The results of this observational study illustrated the range of management practices used in freestall herds in this region and lay the groundwork for future hypothesis-driven studies using this sampled population.

Answer 147

 The prepartum NEFA and Hp threshold associated with culling was ≥0.17 mmol/L and 0.45 g/L, respectively.  The postpartum NEFA and BHB thresholds associated with diagnosis of metritis, displaced abomasum, or clinical ketosis were ≥0.46 mmol/L and ≥0.9 mmol/L, respectively.  Multiparous cows with prepartum NEFA concentration ≥0.17 mmol/L produced 479 kg less ME305. Multiparous and primiparous cows with postpartum NEFA concentration ‚â*0.46 mmol/L produced 280 kg less and 446 kg more ME305, respectively.  Cows with BHB concentration ≥0.9 and ≥1.1 mmol/L produced 552 kg more ME305 and had a 20% decreased risk of pregnancy within 150 d in milk, respectively; however, multiparous cows with BHB concentration ≥1.5 mmol/L produced 376 kg less ME305.  Cows with Hp concentration ≥0.45 g/L produced 492 kg less ME305 and had 28% decreased risk of pregnancy within 150 DIM.  Cows with Hp concentration ≥0.45 g/L had 19% decreased pregnancy risk to first service (PRFS).  Herds above the herd-alarm levels for prepartum NEFA had a 6.0-percentage unit increase in disorder incidence and a 6.0-percentage unit decrease in 21-d pregnancy rate (PR) for multiparous cows, a 3.9-percentage unit increase in PR and a 5.8-percentage unit increase in the probability of pregnancy for primiparous cows.  Herds above the herd-alarm levels for postpartum NEFA had a 5.8- and 4.2-percentage unit increase in disorder incidence for multiparous and primiparous cows, respectively, a 789 kg decrease in ME305 for multiparous cows, and a 6.8- and 6.3-percentage unit decrease and increase in PR and PRFS for multiparous cows, respectively.  Herds above the herd-alarm levels for BHB had an 8.5-percentage unit increase in disorder incidence, a 332 and 229 kg increase in ME305 for primiparous and multiparous cows, respectively, and a 3.2-, 5.2-, and 7.0-percentage unit decrease in PR, probability of pregnancy, and PRFS, respectively.  Herds above the herd-alarm levels for postpartum Hp had a 5.3-percentage unit increase in disorder incidence. At the cow level and herd level, elevated biomarker concentrations were associated with an increased disorder risk and varied performance responses. At the cow level and herd level, elevated biomarker concentrations were associated with an increased disorder risk and varied performance responses.

Answer 148

 Conclusion: the amount of hsa-miR-424-5p was higher in milk sEV from BLV-infected cattle and increasing the hsa-miR-424-5p in milk sEV could be one of the characteristic trends in cattle that are high risk for BLV transmission.

Answer 149

 Bulk tank SCC and the incidence rate of SCM on farms with a CMS were statistically lower than on farms with an AMS, whereas the incidence rate of CM did not significantly differ between both groups of farms.  The AMS farms had more cows per herd treated with antimicrobials at drying-off and a larger proportion of severe CM cases than did CMS farms.  Conclusion: udder health parameters did not differ from those found in Dutch studies before and around the time of implementing SDCT, whereas SDCT was widely applied on Dutch dairy farms during the study period.  Dutch dairy farmers were able to handle the changed policy of antimicrobial use at drying-off while maintaining indicators of a good udder health

Answer 150

 Conclusion: concentrations of hepatic triacylglycerol in early lactation varied substantially, and increments resulted in quadratic association with productive performance, but at the expense of tissue reserves as those cows had increased tissue catabolism and risk of diseases that reduced survival.

Answer 151

 Positive: 588/1,313 BTM samples (apparent herd prevalence of 0.45).  Significant risk factors for herd BTM seropositivity to M. bovis: herd size, the number of neighboring farms, in-degree and country.  Conclusion:  high apparent herd prevalence of seropositivity to M. bovis;  M. bovis infection is now endemic in the Irish dairy sector.

Answer 152

 A key difference between the immune reaction of the 2 genotypes was that the immune response to E. coli was largely contained within the mammary gland of the UH cows (unselected holstein) but became more systemic in the CH cows (contemporary holstein).  UH cows exerted more effective control of E. coli infused into the mammary gland. These data demonstrate that UH cows exerted more effective control of E. coli infused into the mammary gland and thus support the hypothesis that selection practices since the mid-1960s have resulted in CH cows with an immune system that is less effective in fighting intramammary infections. Identification of genetic factors associated with enhanced immune functions that differ between the UH and CH cows could contribute to efforts to reintroduce or enhance beneficial components that have been lost or reduced in the CH cows since the mid-1960s.

Answer 153

 Conclusion: both products had equivalent efficacy for SCM and CM. As the quantity of residual increased, the difference in residual weight recovered increased but this may represent increases in debris rather than indicating a more effective barrier.

Answer 154

 Significant interactions between days in milk with season and parity were observed, where for every 5-d increase in DIM, the odds of clinical mastitis decreased by different proportions depending on the interaction.

Answer 155

 Cows with a purulent vaginal discharge score of 2 or 3, and a ultrasonical examination of endometritis score of 1, 2, 3, or 4 < likely to conceive than cows with a PVD/UE score 0.  Conclusion: higher scores in both tests were associated with impaired fertility, and UE scoring with a threshold of ≥1 had the highest test Se and Sp estimates although test Se was conditional on days in milk when the PBE occurred.

Answer 156

 Conclusion: HC diet can induce SARA with increased concentration of LPS in the peripheral vein, stimulate inflammatory reactions and oxidative stress, and inhibit milk fat synthesis in the mammary gland of dairy cows.

Answer 157

 Among heifers that underwent luteolysis, progesterone concentrations from 18 to 36 h after treatment were lesser in heifers treated with cloprostenol compared with those treated with dinoprost.  Type of PGF2α did not affect progesterone concentrations past 36 h from treatment; however, heifers treated with 2 PGF2α injections had lesser progesterone concentrations and CL blood flow from 36 to 72 h after treatment compared with heifers that received a single PGF2α injection.

Answer 158

* High-milk replacer allowance calves had increased BW during wk 2, 3, 4, 5, 6, and 7. The difference in BW disappeared by wk 8, with overall average daily gain having a tendency to be increased in high (0.57 ± 0.04 kg/d) compared with low-MRA (0.50 ± 0.04 kg/d) calves, whereas average daily gain was increased in high-MRA calves during wk 2 and 3 and increased in low-MRA calves during wk 7 and 8. * increase in rumen mass in low- compared with high-MRA calves, as well as in low- compared with high-Starch starter calves was observed. * The length, width, and 2-dimensional area of rumen papillae were also increased in low- (area: 0.88 ± 0.03 mm2) compared with high-MRA (0.46 ± 0.03 mm2) calves. The majority of differences were attributed to increased MR allowance, which contributed to reduced pelleted starter intake by more than 50% and reduced rumen development, whereas differences in starch intake from the completely pelleted starter had minimal effects on overall growth and tissue measurements.

Answer 159

* Cows fed BC had lower peak milk than cows fed CON (50.9 vs. 55.3), but total lactation milk yield did not differ significantly. * No effects of BC were observed on days to conception (100 d) or times bred (2.4). * Treatments did not affect incidences of ketosis, retained placenta, displaced abomasum, off feed, lameness, footrot, mastitis, or metritis. * In conclusion, in pregnant cows already receiving adequate vitamin A but with low serum β-carotene concentration, supplementation of β-carotene increased concentrations of β-carotene and vitamin A in blood serum, but did not affect production, reproduction, or health.

Answer 160

* The VWP was not significantly associated with the net partial cash flow per cow per year. * A change in milk, feed, or calf price, or a change in labor costs for calving cows or for inseminations had a greater effect on the yearly NPCF of cows in VWP50 compared with cows in VWP200.

Answer 161

* Dietary butyrate supplementation and oral NSAID administration did not affect milk yield or postpartum serum concentrations of amyloid A and haptoglobin. * However, butyrate-fed cows increased plasma fatty acid concentration on d -4 relative to calving (501 vs. 340 μEq/L) and tended to increase serum haptoglobin concentration (0.23 vs. 0.10 mg/mL). * Butyrate-fed cows tended to have lower milk crude protein yield compared with cows fed the control diet (1.21 vs. 1.27 kg/d). * Dietary butyrate supplementation and oral NSAID administration did not have overall positive effects on production performance of dairy cows during the calving transition period.

Answer 162

* Less time spent at pasture under wet soil conditions lowered treading damage but had no effect on annual pasture production (mean 14.8 t of organic matter/ha). * Annual milk solids production per cow was lowest for the control herd (485 kg) and not different between the other systems (503 kg). * Reducing treading damage to swards did not improve productivity or profitability of the grazing systems.

Answer 163

* For the proportion of the season milked 3-in-2, there was a significant effect on milk (−11%), protein (−8%), and lactose (−12%) yield per cow per year, but no effect of fat. * Additionally, there was a positive effect (+6%) on body condition score before dry-off * There were no differences in estimated feed eaten, or pasture herbage accumulation, composition, or quality. Therefore, pasture management and feed allocation under 3-in-2 should be similar to TAD. * On commercial farms, the degree to which reduced milk income can be offset by lower costs will be highly farm-specific, but opportunities for savings were identified in the results. * The short walking distances on the research farm and potential to improve farm management using the time saved from fewer milkings suggests better production may be achieved with 3-in-2 milking on a commercial farm.

Answer 164

* Results suggest that a single intramammary administration of bCNH at dry-off effectively increases milk yield and lowers SCC, prevents new IMI during the dry period, and may be a beneficial alternative for curing existing IMI at dry-off, mainly by CNS.

Answer 165

* The results reported here indicate that restricted dietary P supply during the dry period positively affected the Ca homeostasis of periparturient dairy cows but did not reveal negative effects on DMI, milk production, or metabolic activity in the following lactation. Restriction of P during the dry period was associated with hypophosphatemia antepartum but neither exacerbated postparturient hypophosphatemia, which is commonly observed in fresh cows, nor was associated with any clinical or subclinical indication of P deficiency in early lactation.

Answer 166

* During weaning, hay calves tended to consume increasingly more total mixed ration, significantly more water, and less grain than control calves. * Hay calves also spent less time self-grooming (12% vs. 14%), tongue flicking (14% vs. 18%), and performing NNOM (17% vs. 21%) than control calves. * Overall, we found that hay provision affected most oral behaviors that calves perform; it promoted natural feeding behaviors and reduced abnormal ones, suggesting hay should be provided.

Answer 167

* The provision of drinking water was associated with a greater proportion of observations eating hay but less eating calf starter. * The increase in the proportion of observations eating calf starter with age was greater for calves on a low milk allowance than of those provided a high milk allowance; this is likely due to calves on a low milk allowance searching for nutrients and energy. * Calves on a high milk allowance grew faster and spent more time lying compared with calves with a low milk allowance, thus suggesting greater satiety of well-fed calves. Our results suggest that calves should have free access to drinking water from birth and that access to drinking water may aid in hay (fiber) intake and possibly rumen development.

Answer 168

* However, participants shared that the Canadian supply management system (including processors) required a consistent flow of production, which was thought to be easier and more economically realized with indoor housing of lactating cows. * Participants believed that pasture or outdoor access for dairy cows was desired by the public. * Some participants believed that dairy cows prefer to spend time outside under favorable weather conditions, but others felt that cows preferred to stay indoors in modern, ventilated freestall barns. The results of this study describe the perspectives of dairy farmers regarding the views of dairy industry stakeholders as they relate to outdoor access, helping to inform conversations around the provision of outdoor access for dairy cattle.

Answer 169

* These data suggest that POST HS is associated with performance losses to a greater extent than prepartum HS and that nulliparous and parous cows are prompt to losses associated with exposure to HS during the transition period.

Answer 170

* Contrary to our hypothesis, struggling was most marked in calves that received buffered lidocaine. * Similarly, calves administered unbuffered or buffered lidocaine had elevated heart rates for 1 or 3 min after the first injection, respectively, compared with at the end of the 5-min observation period. Calves in the buffered treatment had lower eye temperatures in the first half of the observation period compared with the second half, consistent with responses cattle show to other aversive procedures, but no changes over time were observed in the other 2 treatments. These results suggest that cornual nerve blocks are aversive, at least in the short term, and that buffering the lidocaine worsens the calf's response to this procedure.

Answer 171

* Thus, nisin and the bacteriocin consortium showed the most promise as a teat disinfectant by reducing staphylococci, streptococci, and total bacteria counts.

Answer 172

* Changes in BCS were calculated by periods of interest as change from dry-off to calving (multiparous cows); change from calving to 21 DIM; change from calving to 56 DIM; and change from calving to first artificial insemination and assigned into categories as large loss of BCS (top 25% of cows losing BCS); moderate loss (bottom 75% of cows losing BCS); no change (ΔBCS = 0); or gain of BCS (ΔBCS > 0). * cows with large loss in BCS between calving and 21 DIM, calving and 56 DIM, and calving and first artificial insemination had lower odds of P/AI1 compared with other categories of ΔBCS within the same period of interest. * Being in the lower quartile at any time point post-partum was a risk factor for decreased odds of P/AI1 * Overall, low BCS and more pronounced reductions in BCS occurring closer to first artificial insemination resulted in lower odds of pregnancy per artificial insemination.

Answer 173

* Despite differences in circulating concentrations of nutrients and hormones before challenge, metabolic responses to systemic inflammation did not differ between the 2 treatments. We conclude that AA infusion changed metabolic status and milk fat but did not appear to alter the metabolic response to subsequent systemic inflammation.

Answer 174

* We conclude that AA infusion before systemic inflammatory challenge decreased the anti-inflammatory response but did not alter concentrations of other systemic markers of inflammation.

Answer 175

* Overall, the short-term negative energy balance induced by feed restriction was temporarily accompanied by metabolic adaptations, but did not alter the studied factors related to the immune system. Metabolic and endocrine adaptations supporting milk synthesis were continued during the first days after dry-off despite cessation of milking. Thus, the abrupt dry-off resulted in a short-term increase of glucose and triglyceride concentrations, with a delayed endocrine response to re-establish nutrient homeostasis in blood.

Answer 176

* Data showed that calves fed the HQH diet consumed more peNDF and this was associated with longer rumination time (591 min/d) and more ruminating boli (709 boli/d) * In conclusion, feeding high-quality hay, instead of concentrate-rich starter feeds, resulted in improved rumination and ruminal fermentation profile, without affecting ruminal pH and systemic and stress health variables.

Answer 177

 Milk synthesis rate decreased with increasing SCC, LDH, and EC, but in a nonlinear fashion.  The thresholds at which milk synthesis rate started to decrease were 2.5 LnSCC (12,000 SCC/mL) to 3.75 LnSCC (43,000 SCC/mL), 0 to 1 LnLDH (1-2.7 U/L), and 5.0 to 6.0 mS/cm for EC.  Another substantial decrease of milk synthesis rate was observed at thresholds of 5.625 LnSCC (277,000 SCC/mL) and 3 LnLDH (20 LDH U/L) but not for EC.  Having chronic mastitis decreased milk synthesis rate in all models. * The identified nonlinearities between mastitis indicators and milk synthesis rate should be incorporated in statistical models for more accurate estimations of milk loss due to mastitis.

Answer 178

 > isolation rate of Trueperella pyogenes in CE cows compared with healthy and SCE cows.  Some anaerobic species were exclusively isolated from the CE group, even though they presented lower frequency.  18.1% of samples from CE cows and 40% of SCE cows were negative to bacterial isolation. * The method of sample collection, culture, and identification by MALDI-TOF MS were essential for the success of the analyses.

Answer 179

* These findings suggest that feeding RP-Glu during the periparturient period can increase digestive capacity and feed intake, and decrease mobilization of body fat and protein immediately after calving without increasing milk production.

Answer 180

Combined application of both technologies was shown to return a greater annual ΔPROF on average compared with that achievable from TAI alone. * However, the risk of not returning a positive annual ΔPROF varied across the scenarios with higher risk in TCONV-H (conventional semen in heifers) and TSEX-HC (sexed semen in heifers and cows) * Sensitivity analysis showed that when hormone costs increased by €10/cow TCONV-H and TSEX-HC had a 38 and 23% chance, respectively, of not returning a positive annual ΔPROF

Answer 181

These results, in combination with many participants' concern for the importance of the mother cow-calf relationship and perceptions that severing of this bond was a breach of standard of care, suggest that there may be low acceptance of any cow-calf management system involving early separation as such systems are unlikely to resonate with underlying values.

Answer 182

* This study demonstrated that a 1-kW heat lamp was effective in increasing ADG in calves, and no significant effect of calf jacket on ADG was found. * A significant, positive effect of increased pen temperature on calf ADG was identified in this study and was reinforced when including prior information from previous research within a Bayesian framework.

Answer 183

* In conclusion, the present work demonstrated that the heat treatment of colostrum ≤60°C decreased colostrum IgG by 5.38 g/L for LT and increased serum IgG by 2.65 g/L and STP by 0.21 g/dL.

Answer 184

* In conclusion, transdermal flunixin meglumine given at the time of disbudding combined with local anesthesia decreased concentrations of the stress biomarker cortisol, but a second dose 6 h after disbudding had no further effect on plasma cortisol levels.

Answer 185

* Overall, these data suggest that reducing both milking frequency and feed quantity in the AMS is the most efficient method to decrease milk yield before dry-off, without negatively influencing milking frequency or yield in the next lactation, as well as without affecting milk quality.

Answer 186

* In conclusion, farmer psychosocial factors were associated with strategies for BVD control in UK cattle farmers. Psychological proximity to veterinarians was a novel factor associated with proactive BVD control and was more important than the more extensively investigated trust. These findings highlight the importance of a close veterinarian-farmer relationship and are important for promoting effective BVD control by farmers, which has implications for successful nationwide BVD control and eradication schemes.

Answer 187

* Risk factors for high incidence of SDSD-IMI in freestall dairy herds were related to housing, including closed flooring in alleys and rubber mats in cubicle bases. * Parlor milking was also a risk factor compared with automatic milking systems. * From herd visits, a considerable proportion of extramammary samples were SDSD positive, particularly from wounds and skin of the animals and the cubicle bases. Samples from mucous surfaces (nostrils, rectum, and vagina) and water troughs were least frequently positive. * No significant association was identified between sampling site (milk, body sites, and environment) and SDSD sequence types. * Findings in this study suggest that SDSD is a cow-adapted opportunist with potential for contagious transmission, and that the freestall environment is likely to play a role in transmission between cows.

Answer 188

* Our results demonstrate that in pasture-based seasonal calving herds, confounding between pregnancy status and spectral changes associated with stage of lactation can inflate prediction accuracies. When the effect of this confounding was reduced, prediction accuracies were not sufficiently high enough to use as a sole indicator of pregnancy status.

Answer 189

* diet supplemented with compound probiotics had no effects on the body weight, average daily gain, dry matter intake, and feed efficiency. * At 90 d of age, diet supplemented with compound probiotics decreased the withers height. * Immunity activities increased in the high compound group, supported by the increased concentrations of serum total protein and immunoglobulins at 40 d of age, and by the increased activity of superoxide dismutase at 80 d of age. * Diet supplemented with compound probiotics altered rumen fermentation, by decreasing rumen acetic acid and propionic acid, and increasing butyric acid concentrations. * Diet supplemented with compound probiotics improved the health status of calves, indicated by the decreased fecal score at 3 wk of age and the medicine usage In summary, although diet supplemented with HP (1.2g) decreased the withers height, this level of probiotics is recommended to improve rumen development and health status of newborn Holstein calves.

Answer 190

 The majority of the controlled trials assessed prevention of nonambulatory conditions, most commonly through supplementation of vitamin D and calcium or the provision of anionic salts.  Frequently measured risk factors for becoming nonambulatory: blood calcium, phosphorus and magnesium, and other factors such as parity and breed.  Commonly measured prognostic indicators: calcium, phosphorus, and duration of recumbency  Nonambulatory disorders were measured as risk factors, with the most commonly assessed outcomes including disorders of the transition period, and death or euthanasia.  Milk fever and parturient paresis.

Answer 191

 The lowest satisfaction scores and the highest number of “unable to assess” responses were for the item relating to cost.  Factors that contributed to RAMP (Risk assessment and management plan)-specific producer satisfaction were not identified from the demographic and herd information available in this study.  The knowledge scores indicated moderate knowledge about JD and fair knowledge about BVD and BLV.  Bovine viral diarrhea knowledge scores were not found to differ based on whether or not the certified veterinarian discussed BVD during the preceding RAMP, but BLV knowledge scores were higher among dairy producers that discussed BLV during the preceding RAMP. * Strengths and gaps in producer knowledge about these 3 infectious diseases were identified.

Answer 192

* Higher concentrations of Ca, Mg, Na, Zn, Fe, and Cu, and total yields of Mg, Zn, Fe, and Cu were observed at first- compared with second-milking colostrum. * Serum and first-milking colostrum Cu concentrations were positively associated, but no significant associations were observed between other minerals' serum and first-milking colostrum concentrations or total yields. * Parity was associated with first-milking colostrum Ca, P, K, and Fe concentrations and yields; younger multiparous cows had higher concentrations and total yields of these minerals. * Mineral total yields were linearly associated with first-milking colostrum yield * In conclusion, variation in first-milking colostrum mineral concentrations and total yields across cows could be partially explained by cow parity and colostrum yield.

Answer 193

* Total DM intake and daily weight gain of calves were not affected by the starter feed during the first 8 wk of life. However, from wk 9 to 14, calves fed the MQH diet had lower DM, ME, and CP intake and gained less weight than calves from the other experimental groups. * In conclusion, feeding high-quality hay can fully replace starter concentrates in the feeding of dairy calves without adverse effects on performance during the rearing period, while increasing forage fiber intake and utilization, which enhanced ruminal ketogenesis and cholesterogenesis around weaning.

Answer 194

* The SARA episodes increased concentration of circulating SAA and tended to increase that of IL-1β. * Induction of SARA did not affect the concentrations of circulating IL-6, Haptoglobin, and myeloperoxidase (MPO). * The SCFP supplementation reduced plasma concentrations of LTA and SAA and serum concentration of IL-1β compared with control. * Additionally, higher level 38 d/d of SCFP tended to reduce ruminal LPS in second-parity cows compared with control. Overall, SCFP supplementation appeared to stabilize the rumen environment and reduce proinflammatory status, hence attenuating adverse digestive and inflammatory responses associated with SARA episodes.

Answer 195

* New IMI proportion was lower among quarters assigned to the CMT than SCC-group [101/3,212 (0.032, 95% CI 0.025–0.038) versus 142/3,232 (0.044, 95% CI 0.036–0.051)]. * There was no difference in incidence of clinical mastitis between treatment groups. * The total mass of antimicrobials used was 63% higher in the CMT-group than in the SCC-group (3.47 versus 2.12 mg/kg of liveweight). Selection of quarters for antimicrobial treatment at the end of lactation based on CMT resulted in greater proportion undergoing bacteriological cure, reduced risk of any new IMI and reduced post calving prevalence of any IMI compared with selection of cows based on SCC. However, CMT-based selection resulted in higher antimicrobial use compared with SCC-based selection, and further research is required to analyze the cost benefit and impact on risk of antimicrobial resistance of these 2 strategies.

Answer 196

Ex vivo * Cows with SCK had greater levels of Hp, SAA, IL-1β, IL-6, IL-8 and TNF-α. These proinflammatory factors had strong positive correlations with myeloperoxidase (MPO), a marker protein of PMN AG, whose content was greater in the serum of SCK cows. * Both the number of AG and the protein abundance of MPO were lower in PMN isolated from SCK cows. Additionally, we found a greater degree of AG degranulation in cows with SCK. In vitro experiment: * After FFA treatment, release of intracellular MPO was increased confirming that FFA promoted degranulation of AG. Overall, the present study revealed that high blood concentrations of FFA in SCK cows induce the production of NADPH oxidase-derived ROS, thereby promoting degranulation of AG in PMN. The stimulatory effect of FFA on the release of AG content during degranulation, especially MPO, provides a new insight into the systemic inflammation experienced by peripartal cows with SCK.

Answer 197

* Communication skills were evaluated utilizing 3 assessment tools; 1. an objective structured clinical exam (OSCE), 2. standardized client feedback, 3. and an instrument designed for veterinary participants to assess their self-efficacy. * Study results showed that before training, communication skills of participating veterinarians had limitations, including skill deficits in communication tasks strongly associated with increased adherence to veterinary recommendations. * Based on the 3 assessment tools, communication skills of participating veterinarians improved with the training provided. * All 3 assessment tools identified significant increases in communication skills

Answer 198

* Seroneutralization antibody titres postvaccination for the PI3 virus were higher for the FO than the CO group. * In conclusion, calves supplemented with FO had lower concentrations of blood lactate, haptoglobin, IL-1β and TNF-α than calves supplemented with CO during the study period. Results of this trial should be interpreted with caution due to the lack of a negative control group as well as the lower birth weight and growth rate observed under heat stress conditions.

Answer 199

1. Pairs of calves spent less time outside as the amount of rain increased. 2. During the first 6 wk of age, time spent outside increased, but time spent outside decreased between wk 6 and 7, and remained around 200 min/d from wk 7 to 11. 3. Calves with the highest average daily gain and calves that were approximately 50% white appeared to spend more time outdoors. * When calves were outside they appeared to spend a greater proportion of their time standing than when they were indoors during the first 4 wk. * These results indicate that, when given the option in the summer, calves make use of an outdoor space, but this appears to vary with weather, calf age, average daily gain, and coat color.

Answer 200

* Of the 32 oxylipids detected, concentrations of 7 differed between cows with no detected disease and diseased cows throughout the sampling period.

Answer 201

* Overall, the SA and LDH had similar ability to predict IgG transmission from blood into milk. Comparing the areas under the curve (AUC) of the ROC curves, the SCC-LDH versus SCC-SA had lower gram-positive (AUC = 0.984 vs. 0.986) but similar gram-negative (AUC = 0.995 vs. 0.998) IMI prediction ability. * The SCC, IgG, LDH, and SA were greater in gram-negative than in gram-positive IMI (BME and AME) in early lactation. * In conclusion, LDH and SA could be used as replacement markers to indicate the presence of IgG transfer from blood into milk; in combination with SCC, both SA and LDH are suitable for differentiating IMI type, and before milk injection is better for mastitis detection in after milking secretion .

Answer 202

* BW was greater for the CT treatment compared with the others from d 0 to d 7, whereas BW of severe restriction was lesser compared with the others from d −1 to d 7. No differences among treatments were observed at weaning. * Similarly to BW, no differences in concentrate intake among treatments were observed at weaning on d 42 of the study. * At d −1 for SV and d 0 in all restricted calves, serum glucose concentration was lesser compared with CT. * At d −1 and 0, nonesterified fatty acids and BHB serum concentrations were greater in the SV calves compared with the other treatments. * By d 2, serum concentrations of nonesterified fatty acids, BHB, and glucose were restored to CT levels. * At d −1 serum citrulline concentration was lesser in SV and greater in MD calves. Results showed that degree of dietary restriction, type of liquid diet (MR or rehydrating solution), and fasting hours (9 vs. 19 h) affected calves' BW, concentrate intake, and serum concentration of markers indicative of energy status and gastrointestinal permeability.

Answer 203

* Cows with typical cycles treated with hCG (hCG7 and hCG7+13) had a later onset of luteolysis, prolonged time to undergo complete luteolysis, and greater proportion of cows with 3 follicular waves than CON, resulting in a longer interovulatory interval for hCG7 and hCG7+13 than CON

Answer 204

o treatments and exposed to 6-h light-dark phase shifts every 3 d until parturition. * Treatment did not affect levels of CORT, GH, or P4 at 0600 h, but overall level of serotonin was lower and MEL higher in PS cows across days sampled.

Answer 205

Our results indicate that moderate-yielding dairy cows undergo similar homeorhetic changes to high-yielding housed cows; however, differences in diet composition result in greater BHB concentrations than expected, based on their milk production and NEFA concentrations. In addition, most cows were able to transition to a state of higher energy requirement following calving, albeit with an increased metabolic challenge in the liver, and only a small percentage of cows were classified with severe hepatic lipidosis or severe hyperketonemia. Increases in metabolic function of the liver were accompanied by changes in indicators of the immune system and changes in mineral balance that, combined, probably reflect the innate response to the transition from gestation to lactation.

Answer 206

* In summary, AGD measured at birth did not reflect AGD at breeding age in heifers, but AGD measurements in cows had high repeatability at all stages of the estrous cycle, gestation, and lactation, except at 270 d of gestation. Therefore, AGD could be measured reliably at any of the aforesaid physiological states in cows due to its high repeatability, except during late gestation. The earliest gestational stage when pregnancy-associated increase in AGD occurred, however, could not be definitively established in the present study.

Answer 207

 Prior to weaning: in High calves: lower starter intake, higher ADG  Greatest growth in calves fed high milk, and high CP%.  Feeding starters with a higher proportion of CP may help maintain a more balanced ratio of CP to ME during high milk feeding, to avoid protein deficiency due to low starter intake. When calves are fed a high milk allowance, urine excretion of PD may be misinterpreted as a measure of estimated microbial growth and rumen development; this should be considered during calculations of estimated microbial yield in milk-fed calves.

Answer 208

 Increasing feeding rate improved BW gain and structural growth, delayed abomasal emptying under heat stress conditions  Increasing feeding frequency accelerated abomasal emptying and might reduce heat load of preweaning dairy calves

Answer 209

 Feeding frequency of TID enhanced peripheral tissue insulin response  MR feeding frequency significantly affects glucose metabolism in the calf, which, however, did not seem to affect body growth.

Answer 210

 Feeding a prepartum negative DCAD diet altered blood acid-base balance and induced metabolic acidosis at calving, and improved protein and lipid metabolism.  Supplementation of high Ca in the negative DCAD diet prepartum was more favorable to metabolic adaptation to lactation in dairy cows than the negative DCAD diet with low Ca

Answer 211

 Increases in 2-day-lagged minimum temperature (both indoor and outdoor) negatively affected the average milk yield depending on the parity group (primiparous vs multiparous cows).  Primiparous cows were more affected than multiparous cows, but the effect size was small.  Primiparous cows decreased 0.006 kg/d for every degree increase in 2d-lagged-temperature  Prolonged high temperatures over a few days were more important than short-term (temporary) high temperatures over 1 or 2 days.

Answer 212

 Calving ease, calf size, and twinning greatly affected offspring longevity  Offspring with the longest life were associated with medium or large birth size and unassisted calving  Small offspring, the result of twins, had the shortest lives  Offspring that resulted from an unassisted or surgery calving and classified as large or medium when they were born were in the group with the highest length of productive life  Offspring resulting from a malpresentation or pull in a twin birth were in the group with the lowest length of productive life

Answer 213

 Calves that were more playful/exploratory consumed more milk per day preweaning and more concentrate per day over the experimental period.  Calves that were more vocal/active (interpreted as a type of sociability trait where vocalizations and pacing serve to communicate with conspecifics when isolated from herd) had lower preweaning milk intakes and lower concentrate intakes over the experimental period.

Answer 214

 For a cow likely to have intramammary infection, a missed aDCT treatment undesirably affects subsequent lactation milk yield and somatic cell count.  For cows with an SCC of 200,000 cells/mL before dry-off, compared with untreated cows, aDCT-treated cows produced 0.97 kg/d more milk and, at 45 DIM, had an SCC that was 20,000 cells/mL lower. Our findings indicate that a missed aDCT treatment for a high-SCC cow has a negative effect on subsequent lactation milk yield and SCC, which emphasizes the importance of accurate selection of cows to be treated.

Answer 215

 The once a day milking group showed rapidly and markedly decreased blood BHB concentrations  During the 2wk treatment period, cows milked once daily produced 26% less milk and 25% less energy-corrected milk than the TDM cows.  A 2-wk reduction of milking frequency in ketotic cows from twice to once daily with treatment with propylene glycol resolved ketosis and decreased blood BHB concentrations more effectively than treating TDM cows with PG alone

Answer 216

 Cow-level risk factors for increased lameness prevalence were age and genetic predicted transmitting ability for lameness.  Herd-level risk factors included farm and herd size, stones in paddock gateways, slats on cow tracks near the collecting yard, a sharper turn at the parlor exit, presence of digital dermatitis on the farm, and the farmers' perception of whether lameness was a problem on the farm

Answer 217

 Calves transported at 28 d had a more advanced adaptive immunity than calves transported at 14 d of age.  The extent of development of adaptive immunity was associated with the risk of treatment at the veal farm  Calves transported at 28 d of age had a lower probability of individual treatments with medicines other than antibiotics (e.g., anti-inflammatories, multivitamins, and anti-coccidial drugs), a lower mortality risk, and a higher carcass weight than calves transported at 14 d of age.

Answer 218

 The reduced pulsation, reduced pulsation and vacuum methods increase parlor efficiency and are work-saving alternatives to manual preparation methods including an adequate prestimulation (LPrep).  However, shortening prestimulation to a 5-s teat cleaning followed by a latency period and milking at regular vacuum and pulsation did not represent an adequate duration of prestimulation and is not adequate to save occupancy time.  Because milking was performed at a relatively low vacuum (44 kPa) and at a detachment level of 400 g/min, teat tissue thickness did not differ among MR, and the vacuum reduction in RPV did not cause an additional advantage for teat condition compared with RP.

Answer 219

 Feeding a sodium acetate-based oral electrolyte solution limited the increase in abomasal pH and ability of E. coli to grow in abomasal contents, regardless of whether the calves were fed oral electrolytes alone or 30 min after a milk feeding.

Answer 220

 Treatment led to a considerable increase in serum Ca in the first 10 d after parturition  BUT injection of 12 × 106 IU of cholecalciferol had a negative effect on inflammatory response, milk production in early lactation, and ultimately on reproductive performance.

Answer 221

 Colostrum quantity:  Primiparous cows: Affected by month of calving (Apr>Nov), sex of the calf (Male>Female), stillbirth  Multiparous cows: Affected by month of calving (May>Oct), calving ease, sex of the calf (Male>Female), previous lactation MY, days spent in the far off group, days in the close up pen  Colostrum quality:  Primiparous cows: Affected only by month of calving (Dec>Aug)  Multiparous cows: Affected by parity (3+>2), month of calving (Feb>Aug), milk yield, colostrum quantity We observed a seasonal pattern for colostrum quantity and quality. Future intervention studies using multiple farms need to elucidate whether management of the photoperiod or length of exposure to close-up diets, or both, can help to optimize colostrum production.

Answer 222

 Bupivacaine liposome suspension as a cornual nerve block at the time of dehorning was as effective at controlling pain as a multimodal approach of lidocaine and meloxicam

Answer 223

 A single-dose meloxicam treatment showed considerable promise for improving standing ability of low-vitality calves.  Latency and the first attempt to stand were not influenced by the NSAID treatment; however, the time spent standing, the longest standing bout, and the average duration of standing indicated increased standing ability of meloxicam-treated calves with low vitality, but not in normal-vitality calves.  The latency to stand and first attempt to stand were both increased by dystocia

Answer 224

 Punctual assessment of colostrum harvest and feeding equipment cleanliness by luminometry can be useful to differentiate herds according to their hygiene and health characteristics.  The maximal dichotomized luminometry value (<1,000 RLU or ≥1,000 RLU) was associated with hygiene and health dimension. This study gave promising results concerning the potential application of ATP luminometry for calf rearing practices assessment.

Answer 225

 Cows with positive genetic merit for fertility traits had longer and more active estrous events, but the inter-estrous interval did not differ between the 2 groups.  The first postpartum estrous event was associated with less activity and was shorter than subsequent estrous events in both fertility groups.

Answer 226

 Respiration rate was the first indicator that showed the cow was reacting to increasing temperature  RH and AV significantly affected the responses of RR, rectal temperature and skin temperature, and productive performance of high-producing Holstein cows.  All inflection point temperatures were lower under long exposure time than under short exposure time.  These responses already occurred at moderate ambient T of 19 to 26°C. We concluded that RH and AV significantly affected the responses of RR, RT, ST, and productive performance of high-producing Holstein cows. These responses already occurred at moderate ambient T of 19 to 26°C.

Answer 227

 Cows with greater estrous expression had greater pregnancy per AI than those with lesser expression  GnRH administration was found to increase fertility in cows with reduced estrous expression but not for those with greater intensity of estrous expression  Increased ovulation rates do not seem to be the direct mechanism behind this relationship.

Answer 228

 Differences between positive and negative cows occurred across the transition period; however, markers returned to reference intervals within 4 d after calving indicating minor effects of fertility breeding value on transition period adaptation.  Magnesium and aspartate aminotransferase concentrations differed between cows with short and long postpartum anovulatory intervals from wk 4 postcalving, which appear to be related to estrus. The profound differences in reproductive performance among the groups was not explained by underlying differences in metabolic responses during the transition period.

Answer 229

 Phosphatidylglycerol lipids were mostly absent in cow plasma, but concentrations were high in colostrum and correspondingly found circulating in the calf.  Nonesterified fatty acid concentration had a positive relationship with total triacylglycerol content of plasma samples at 1 wk prepartum, and a negative relationship with total membrane lipids and phosphatidylglycerol concentration of colostrum  Plasma fatty acid profiles and fatty acid composition of colostrum were related to the metabolic status of the cow, and colostrum might be the source of phosphatidylglycerol in calf circulation, but dam circulation is not the source of phosphatidylglycerol found in colostrum

Answer 230

 There was little difference in average rumination time among all systems.  The total time spent ruminating averaged 444 min/d and occurred in 13.8 bouts/d that averaged 32.7 min.  Rumination time was quadratically increased with increasing milk fat yield (partial R2 = 0.27) and milk fat percent  Rumination was also increased with increasing milk yield, dry matter intake, and rumen pH, and was quadratically related to dietary neutral detergent fiber (NDF) and total-tract NDF digestibility In conclusion, rumination time was related to milk fat across a large number of studies, although it explained only a limited amount of the variation in milk fat.

Answer 231

 Milk metabolites and fatty acids are potential noninvasive indicators of energy status of early-lactation dairy cows.  Milk isocitrate, Σ C6:0 to C15:0. and cis-9 C18:1 had the best single linear regressions with EB  Milk concentrations of ∑ C6:0 to C15:0, C18:0, cis-9 C18:1, and ∑ OBCFA >C16 presented some of the best correlations and regressions with other indicators of metabolic status, lipomobilization, and EB Metabolites and FA secreted in milk may serve as noninvasive indicators of metabolic status and EB of early-lactation cows.

Answer 232

 Both cow genotype and parity affected dry matter intake, milk production, and production efficiencies of grazing dairy cows.  Dry matter intake was:  HF - 17.2 kg/cow/day  Jersey x HF = , 17.0 kg/cow/day  Norwegian red x (Jersey x HF) = 16.7 kg/cow/day  DMI increased linearly with parity. Although all 3 genotypes achieved high levels of DMI and production efficiency, JEX achieved the highest production efficiency. Some of the efficiency gains (SCM/100 kg of BW, MSo/100 kg of BW, and total DMI/100 kg of BW) achieved with JEX decreased when the third breed (Norwegian Red) was introduced.

Answer 233

 Supplementation increased plasma n-3 PUFA concentrations, decreased the calving-to-conception interval, and modulated plasma adiponectin expression, evincing a beneficial effect on reproductive performance of high-yielding dairy cows.  milk yield improved with increased intake of fat supplements  Conception rate to first AI increased with higher intake of both fats, but a decrease of calving-to-conception interval occurred only in n-3 PUFA cows. In conclusion, this study evinced a positive linear relation between rumen-protected linseed fat intake and plasma n-3 PUFA concentrations, which modulated adiponectin expression and improved reproductive parameters.

Answer 234

 Unused RMS generally contained higher bacterial counts than did unused straw  Klebsiella spp, Salmonella spp, and L. monocytogenes were more frequently detected in unused RMS  Overall, animal and human pathogens were found in greater numbers and more frequently in unused RMS than unused straw

Answer 235

 Uterine discharge (i.e. endometritis or metritis) was associated with unfavorable effects on the female fertility traits calving interval, interval from calving to first service, days open, and nonreturn rate after 90 d, but was unrelated to 305-d lactation records for production traits milk yield, protein yield, and fat yield  Heritabilities were close to zero  15 SNPs associated with UD were identified.  Different SNP significantly influenced different UD stages, explaining the inter-individual variations in clinical severity of uterine infections.

Answer 236

 Results revealed genomic regions and candidate genes associated with calcium homeostasis. We also identified biological pathways and molecular mechanisms affecting postpartum calcium concentration.  Association mapping identified 2 major regions located on Bos taurus autosome (BTA)6 and BTA16 that explained 1.2% and 0.7% of additive genetic variance of Ca concentration.  The genomic prediction of calcium concentration is possible, which could help to reduce periparturient hypocalcemia in dairy cattle

Answer 237

 Increased SCC is associated with changes in milk metabolite fingerprint and highlights the potential use of different metabolites as novel indicators of udder health status and milk quality.  Samples with high SCC associated with:  Lower levels of riboflavin, galactose, galactose-1-phosphate, dimethylsulfone, carnitine, hippurate, orotate, lecithin, succinate, glucose, and lactose  Greater levels of lactate, phenylalanine, choline, acetate, O-acetylcarnitine, 2-oxoglutarate, and valine Our study suggests that increased SCC is associated with changes in milk metabolite fingerprint and highlights the potential use of different metabolites as novel indicators of udder health status and milk quality.

Answer 238

 Mean calf serum IgG concentration was lower for calves fed pooled colostrum compared with those that received colostrum from a single cow.  Antibodies to infectious bovine rhinotracheitis had a greater period of survival among calves fed own-dam colostrum  Feeding single-dam colostrum can thus improve calf immunity through increased serum IgG levels and antibody survival rates.

Answer 239

 Overall, to the best of our knowledge, this is the first study that has analyzed the correlation between age first rumination and other indicators. We found that earlier AFR was associated with shorter duration of non-nutritive oral behavior, longer durations of rumination and eating the bedding, and higher feed intake by 30 d of age.

Answer 240

 The pool-milk sampling strategy seems well suited to distinguish between herds with a MAP-Ab-WHPapp ≥ 5% and herds with a MAP-Ab-WHPapp <5%

Answer 241

 Compared with twice-a-day milking, plasma calcium concentration was higher for delayed-milking and tended to be higher for restricted-milking cows without negatively affecting future milk yield or composition; however, delaying milking resulted in an inadequate supply of good-quality colostrum.

Answer 242

 Very small stalls caused changes in behaviour (latency to entering the parlor) and total milk yield  The first cow per milking batch required more time (on average >40 s) to enter very small stalls

Answer 243

 No critical differences were found between treatment groups regarding their microbiome or resistome composition in this study

Answer 244

 feeding 3 g/d of FSP may be more beneficial in improving the weight gain and skeletal growth (heart girth and hip width) and in reducing the susceptibility to and duration of diarrhoea and pneumonia in dairy calves.

Answer 245

 Different criteria should be used for optimal CEM diagnosis in primiparous versus multiparous cows (% PMN threshold; sampling time in lactation)  Primiparous cows at 30–40 DIM, using a threshold of ≥7%PMN  Multiparous cows at 60–70 DIM, using a threshold of ≥4%PMN

Answer 246

 Lesions with improved wound healing had at least one of the following criteria when compared with the previous observation: decreased defect size, healthier granulation tissue color (pink-red instead of purple-grayish), more regular aspect of granulation tissue surface, wound contraction, or epithelization starting from the surrounding skin.  Lesions treated with the enzyme alginogel had a decreased adjusted odds ratio for M-score improvement (aOR: 0.04; 95% confidence interval: 0.01-0.11). Lesions treated with the coppergel mostly transitioned to chronic lesions, whereas lesions treated with the enzyme alginogel mostly remained active lesions.  The wound healing progress of almost 70% of the lesions treated with coppergel could not be scored, for the greater part due to the presence of crust materials. With these unscorable lesions classified as "improved," there was no treatment effect on wound healing progress (aOR: 0.99; 95% confidence interval: 0.34-3.05), whereas with unscorable lesions classified as "not improved," the enzyme alginogel outperformed the coppergel with regard to wound healing progress (aOR: 2.48; 95% confidence interval: 1.07-5.79).  None of the products used in our study achieved high cure rates (transition to the M0 stage) for active DD lesions.

Answer 247

 Cows in later stages of pregnancy were less likely to defecate whilst lying in the stall,, with no effect of weight, parity, age, or lameness.  Also, the more time that cows spent lying down, the greater the likelihood of the defecation whilst lying in the stall, but the cow-to-stall ratio had no effect. Increased time perching increased the likelihood of defecating while recumbent, perhaps because perching cows were less dominant or more reluctant to stand up once lying down in the stall. Overstocking did not increase defecating while recumbent, likely because cows spent less time lying down. Together, these results indicate that defecating while recumbent can be common, and points to some of the cow-level factors associated with this behavior.

Answer 248

 3 different postmilking teat treatments  0.215% chlorhexidine  3.5% lactic acid  Negative control, no dipping  Chlorhexidine or lactic acid treatment was associated with a decreased proportion of coagulase-negative staphylococci (CNS)  An increased proportion of species belonging to the genus Corynebacterium was observed especially under the application of lactic acid.  Although both teat disinfectants were basically effective, isolates differed in their susceptibility to both teat disinfectants.  Populations of CNS, Staphylococcus aureus, and Corynebacterium spp. showed significantly lower absolute MIC values for chlorhexidine.  Compared with other species, Corynebacterium spp. showed the lowest susceptibility to either disinfectant

Answer 249

 Restriction of the phosphorus supply limited to the last 4 wk of pregnancy is sufficient to mitigate the risk of hypocalcemia around parturition, through mechanisms primarily driven by increased bone tissue mobilization.

Answer 250

* Mean farm ADG was higher for calves on INT farms than CON farms for both male beef (MB, +0.22 kg/d) and dairy heifer (DH, +0.03 kg/d) calves. The MB calves on INT farms had significantly increased mean ADG (0.12 kg/d, 95% confidence interval: 0.02-0.22) compared with CON farms. * No significant differences were observed between intervention groups for morbidity or mortality. * Implementing one additional intervention from the plan, regardless of intervention group, was associated with improvements in mean ADG for DH calves of 0.01 kg/d (0.01, 0-0.03) and MB calves of 0.02 kg/d (0.00-0.04). * Model predictions suggest that a farm with the highest number of interventions in place (15) compared with farms with the lowest number of interventions in place (4) would expect an improvement in growth rates from 0.65 to 0.81 kg/d for MB, from 0.73 to 0.88 kg/d for DH, a decrease in mortality rates from 10.9% to 2.8% in MB, and a decrease in diarrhea rates from 42.1% to 15.1% in DH. * The calf health plan tested in this study represents a useful tool to aid veterinarians and farmers in the implementation of effective management interventions likely to improve the growth rates, health, and welfare of preweaning calves on dairy farms.

Answer 251

 The results highlight the importance of minimizing lameness prevalence, using sand bedding, ensuring adequate feed access and feed bunk space, and ensuring proper cow body condition to optimize herd-level productivity and milk quality in automated milking herds

Answer 252

 Bacteremia was substantially more common in calves with depression and fever (T>39.7C).  Bacteremia was rare among calves without observed depression.  Antimicrobial therapy targeting bacteremia is not currently justified in routine cases of diarrhoea in preweaning calves without signs of depression

Answer 253

 GnRH did not improve ovulation rates, progesterone level 7 d after insemination, or pregnancy outcomes on any of the farms.

Answer 254

 Follicular wave and progesterone concentration during follicle growth did not affect the signal for maternal recognition of pregnancy (uterine interferon tau), conceptus length, or gene expression measured in conceptuses and endometrium of pregnant cows on d 17 of gestation  These factors did not affect conceptuses and endometrium transcriptome in pregnancies that are maintained to d 17.

Answer 255

 Early-lactation cows have more robust responses to calcemic perturbation (i.e. were better at maintaining eucalcaemia) and have increased circulating and mammary serotonin content relative to nonlactating counterparts, while also indicating that serotonin does not directly respond to decreased blood calcium concentrations. Mammary PTHLH expression was increased in EL cows, with highest expression observed in EL EGTA-infused cows (induced hypocalcemia).  Collectively, our data demonstrate the differential physiological responses of nonlactating, nonpregnant and early-lactation cows during calcium perturbation and offer insight into the role of serotonin and parathyroid hormone-related protein during lactation.

Answer 256

 Milk nitrogen efficiency increased with the lower-protein diet;  Dry matter intake, milk yield and composition, and incidence of diseases were not affected by metabolizable protein supply

Answer 257

 Reducing the DCAD induced a compensated metabolic acidosis that increased apparent absorption of Ca and Mg and concentrations of ionized Ca in blood prepartum and on the day of calving and those of Mg postpartum  Reducing the DCAD had effects on reducing morbidity  Treatment did not affect the incidence or prevalence of subclinical hypocalcemia, hepatic composition, or the prevalence of fatty liver.  Reducing the DCAD had a quadratic effect on incidence of fever, uterine diseases and morbidity. Feeding a diet with -50 mEq/kg of dry matter promoted moderate changes in acid-base balance, altered mineral metabolism, and benefited health of nulliparous cows; however, further reducing the DCAD to -150 mEq/kg negated the benefits to health.

Answer 258

 Lactating dairy cows responded better to fatty acid supplements enriched in C16:0 (Palmitic) compared with those containing C16:0 and C18:0 (Oleic).  Supplementation increased yields of milk and milk fat but had no impact on milk protein

Answer 259

 ITS administration reduced the likelihood of IMI at calving for all pathogens  Odds of IMI at calving was similar between ITS75 and ITS35 quarters for both NAS and other pathogens  ITS administration at either 75 and 35 d prepartum reduced IMI prevalence at calving in primigravid dairy heifers.

Answer 260

 BCS performed at 5DIM and 40DIM and BCS loss categorized as:  Excessive = ΔBCS ≤−0.75  Moderate = ΔBCS = −0.5 to −0.25  No change = ΔBCS = 0  BCS gain = ΔBCS ≥0.25  Both severe loss of body condition and disease occurrences measured within 40 days in milk affected subsequent cow performance and survival.  Odds of resumption of ovarian cyclicity lower in cows with excessive BCS loss  Odds of pregnancy greater in cows with BCS gain vs those with excessive loss  Cows with any disease had lower odds of resumption of ovarian cyclicity  Reproductive disease associated with lower odds of pregnancy at 150 and 305DIM  MY higher in cows with greater BCS loss. The magnitude of ΔBCS and the health status of early lactation cows should be considered when assessing subsequent cow performance and survival.

Answer 261

 Published hyperketolactic threshold concentrations were used to classify study milk samples into ketolactia groups  mACE (≥0.15 mmol/L), mBHB (≥0.10 mmol/L)  “Normal” (mACE <0.15 mmol/L and mBHB <0.10 mmol/L)  “hyperketolactic” (HYKL; either mACE ≥0.15 mmol/L or mBHB ≥0.10 mmol/L).  mACE and mBHB concentrations were influenced by effects of parity, DIM, and their interaction  Among HYKL samples, mACE was elevated soon after calving and declined over time.  In contrast, mBHB started lower after calving and increased reaching peak concentrations around 30 DIM, and then decreased

Answer 262

 The major risk factors for PVD were calving-related problems, retained fetal membrane, metritis, and days in the close-up diet.  Pregnancy per artificial insemination following the first and second services was reduced in cows diagnosed with PVD compared with cows without PVD.  PVD was associated with increased odds of pregnancy loss after the first service and reduced hazard of pregnancy by 305 d in milk.  Severity of PVD was associated with odds of reproductive success.

Answer 263

 Calves castrated at 28d of age and followed for 8wks post procedure  Surgical wounds were fully healed on average 4 wk after the procedure, but only 1 calf in the rubber ring treatment fully healed within the 8-wk study  Inflammation was greater after rubber ring castration, rubber ring castration associated with less ADG due to, in part, lower starter intake  Calves in the rubber ring treatment spent less time lying down and licked their lesions more frequently.

Answer 264

 Cows without vulvovaginal laceration had 1.91 higher odds of curing of metritis than cows with vulvovaginal laceration.  Cows that developed metritis at >7 DIM had 2.09 higher odds of being cured than cows that developed metritis at ≤7 DIM.  For rectal temperature, each degree Celsius above 39.4°C led to lower odds to be cured than cows with rectal temperature ≤39.4°C.  Cows that had reduced milk production from the day before to the metritis diagnosis had lower odds to be cured than cows with moderate milk production increase  Cows developing metritis at >7 DIM, with increase in milk production, and with a rectal temperature ≤39.40°C had increased likelihood of cure of metritis with an accuracy of 75% Although machine learning algorithms are acknowledged as powerful tools for predictive classification, the current study was unable to replicate its potential benefits. More research is needed to optimize predictive models of metritis cure.

Answer 265

conclusion, delaying PRID removal by 24 h within a 5-d PRID-Synch protocol in experiment 1 suppressed early expression of estrus before TAI, and P/AI for heifers inseminated with conventional semen did not differ between treatments. By contrast, although delaying CIDR removal by 24 h within a 5-CIDR-Synch protocol in experiment 2 suppressed early expression of estrus before TAI, delaying CIDR removal by 24 h tended to decrease P/AI for heifers inseminated with sexed semen. Further, submission of heifers to a 5-d CIDR-Synch protocol for first AI tended to increase P/AI and decrease the cost per pregnancy compared with EDAI heifers.

Answer 266

Plasma progesterone concentrations after first artificial insemination were greater in lactating dairy cows that were  (1) selected for improved genetic merit for fertility and milk production traits;  (2) had prompt resumption of postpartum ovarian cyclicity;  (3) had faster resolution of postpartum uterine disease; and  (4) had better indicators of bioenergetic status during early lactation and at artificial insemination.  Moreover, greater plasma progesterone concentrations were associated with greater pregnancy success.

Answer 267

 The NEM was estimated as 70.2 kcal/metabolic body weight per day.  The efficiencies of use of metabolizable energy and protein are greater for milk when compared with milk replacer and starter feed.

Answer 268

 In dry cows, plasma Ca concentrations were 3.3% greater when cows were fed 2.2 instead of 3.6 g of P/kg of DM  The lowest proportion of hypocalcaemia occurred in cows with low P diets pre and postpartum  The feeding of diets containing 2.2 g of P/kg of DM during the last 6 wk of the dry period and 2.9 g of P/kg of DM during early lactation increased plasma Ca levels when compared with greater dietary P levels. These low-P diets may be instrumental in preventing hypocalcemia in periparturient cows and do not compromise DM intake and milk production.

Answer 269

 Ad-lib diet provided as forages and concentrates separately or as a TMR.  Method of diet delivery had no effect on milk production, enteric CH4 energy losses, urinary N, or maximal manure CH4 emission potential, but neutral detergent fiber (NDF) intake was greater when the diet was delivered as TMR as compared with CF  Daily duration of ruminal pH <5.6 was less when the diet was delivered as TMR and this was associated with an improved NDF digestibility

Answer 270

 Reducing DCAD depressed intake prepartum but had no effect on colostrum yield or composition or postpartum productive performance.  Reducing DCAD increased the proportion of pregnant cows by 305 d postpartum but had no effect on the rate of pregnancy.  Manipulating the DCAD of prepartum diets fed to nulliparous cows did not benefit postpartum production but had some benefit to reproduction.

Answer 271

 Heifers born to 2-yr dams were lighter but produced more milk than heifers from older dams, in addition to having superior genetic merit.  Heifers that were the progeny of 2-yr-old dams were lighter from 3 to 21 mo of age  Reproductive performance, as measured by calving and recalving rates was similar in first-calving heifers of all age-of-dam classes.  Based on the results of this study, there were no disadvantages to keeping replacement heifers from first-calving dams.  The progeny of dams ≥9 yr old had the lowest milk solids production in first (297.8 ± 1.6 kg), second (341.6 ± 1.8 kg), and third lactations (393.2 ± 2.4 kg).  Keeping replacements from dams aged 9 yr and over could not be recommended.

Answer 272

 In almost all situations, when the relative P/AI with SS was ≥85%, use of SS led to an overall increase of the farm net profit  If the relative P/AI with SS was <70%, the use of SS led to a decrease in profitability in all simulations except for when cows were AI’ed to FTAI.

Answer 273

 Respondents reported a lack of communication, especially between hoof trimmers and veterinarians.  These findings suggest a need for increased efforts to facilitate collaboration between farmers, hoof trimmers, and veterinarians to improve lameness management on dairy farms.

Answer 274

 spa type t2445 was correlated with persistence in mammary gland epithelial cells  spa type also associated with biofilm production, the extent of β-haemolysis and cytokine expression profiles This study suggests that determination of the spa type may help predict the severity of the disease and the ability of the immune system to eliminate intramammary infections caused by Staph. aureus.

Answer 275

 Calves fed colostrum replacer with additional antibodies had shorter duration of diarrhoeal illness compared with calves fed only milk replacer. Calves fed milk replacer with antibodies also had shorter duration of diarrhoeal illness compared with calves fed only milk replacer.

Answer 276

 Feeding high quality colostrum reduced scouring duration, enhanced surface area of duodenum and jejunum, and improved FCR during the first 5 wk of calf age. Postpartum calf collection time of calves did not affect small intestine development, but Late calves had higher FCR and required a lesser volume of electrolytes to treat scours compared with Early calves during the first 35 d of life.

Answer 277

 The population of Staphylococcus aureus associated with bovine clinical mastitis in Sweden was shown to be stably maintained on the country level over a period of 15 yrs, represented by the dominance of 3 clonal complexes.  Staph. aureus genotype stability gives important insight about the epidemiology of intramammary infections and is useful for devising strategies for control and prevention of Staph. aureus mastitis.

Answer 278

 Ca ≤2.00 mmol/L associated with higher MY, higher SCC, reduced risk of pregnancy to first service, reduced hazard of pregnancy within 150DIM.

Answer 279

 Close monitoring of feeding and activity behaviours can allow for early detection of respiratory disease in preweaning calves.

Answer 280

 The highest frequencies of resistant Strep. uberis were observed for erythromycin (80.7% resistant, R), tetracycline (R = 59%), and penicillin G (R = 57.8%),  The overall use of antimicrobials was associated with the resistance of Strep. uberis to the antimicrobial tetracycline.

Answer 281

 Maintenance of S. uberis within the dairy cow environment was due to a high proportion of animals shedding S. uberis in faeces  Detection levels were significantly higher for housed cattle compared with those at pasture.  Increased probability of detection if cows were housed in loose straw yards, compared those in straw cubicles.  Parity, stage of lactation, and body condition score were associated with detection.

Answer 282

 The inter-rater agreement of BRD clinical signs was variable according to the clinical sign, and BRD clinical signs were not detected equally between veterinarians, technicians, and producers involved in the veal industry.  Induced cough and ear droop or head tilt assessed with a 2-scale combination of severity were the 2 BRD clinical signs whose reliability was acceptable clinically

Answer 283

 Lying and rumination behaviour changed in cows diagnosed with metritis, but the differences observed depended on climatic/weather variables such as rainfall during the spring and temperature-humidity index during the autumn calving season.

Answer 284

 Double dose of cloprostenol sodium (1.0 mg) resulted in the same pregnancy rate per artificial insemination compared with 1 or 2 doses, 24 h apart, of 0.5 mg of cloprostenol sodium.  However, cows treated with a single dose had greater pregnancy losses in third-plus parity cows, greater luteal blood flow following treatment, indicating reduced luteolysis rates, and reduced pregnancy rate per artificial insemination in nonsynchronized cows.  A double dose (1.0 mg) of cloprostenol sodium may be a feasible alternative for fertility programs based on nondifferent outcomes to the two/24 treatment, lower pregnancy losses, and reduced luteal blood flow disappearance following treatment in third-plus parity cows in comparison with the single treatment.

Answer 285

 There was a clear benefit of an additional PGF2α treatment during the Ovsynch protocol on P/AI (+5.6 percentage units). Despite additional costs for hormones and labour, an additional treatment with PGF2α on d 8 was more profitable in 95% of all scenarios because of the associated increase in fertility.  It turned out, however, that adding a second PGF2α treatment was more profitable in multiparous cows compared with primiparous cows.

Answer 286

 Oscillating (OS) dietary crude protein (CP) concentration may improve nitrogen use efficiency (NUE)  Overall, performance and NUE were unaffected by OS treatment, but apparent total-tract digestibility and milk urea concentration increased:  No difference in DMI, MY, milk component yields did not vary between groups  Milk urea concentration was higher, dry matter digestibility, NDF digestibility was higher for OS compared with ST Overall, performance and NUE were unaffected by OS treatment, but apparent total-tract digestibility and milk urea concentration increased, and transient effects on milk yield and composition occurred in OS cows.

Answer 287

 Calves were randomly assigned to one of 3 treatments:  A rumen-protected blend of B vitamins and choline (RPBV);  A 30:70 mix of a nonprotected blend of B vitamins and choline and fat (UPBV);  Control: fat only (CTRL).  Additional B vitamins and choline did not improve calf performance before, during, or after weaning.

Answer 288

 Hormone use associated with participation in a HH program, use of technologies such as pedometers or activity monitors, AMS farms.  PGF used most often, then GnRH, then Progesterone.

Answer 289

These results show that the addition of BFT to organic pasture improves growth of grazing replacement heifers. Economic analyses also demonstrate that interseeding grass pastures with BFT results in an increased economic return compared with grazing monoculture grass pastures. Grass pastures interseeded with BFT may be a sustainable option to achieve adequate growth of Jersey heifers raised in an organic pasture scenario in a temperate climate. This study confirmed that chemical and physical characteristics inherent to different pasture species have a large effect on herbage intake by grazing cattle. Pastures planted to binary mixtures of nutritious grasses and birdsfoot trefoil increase herbage intake of temperate pastures by grazing Jersey heifers.

Answer 290

 There is a substantial variation in conception rate among Brown Swiss bulls, with more than 20% conception rate difference between high-fertility and low-fertility bulls. We also showed that the prediction of bull fertility is feasible as our cross-validation analyses achieved predictive correlations equal to 0.30 for sire conception rate. Improving reproduction performance is one of the major challenges of the dairy industry worldwide, and for this, it is essential to have accurate predictions of service sire fertility. This study represents the foundation for the development of novel tools that will allow dairy producers, breeders, and artificial insemination companies to make enhanced management and selection decisions on Brown Swiss male fertility.

Answer 291

 An increase in salivary SAA occurs during subclinical mastitis; SAA was higher in SCM cows and demonstrated a positive (weak) correlation with SCC  Cows with subclinical mastitis demonstrated changes in activity:  Distance moved, social exploration, social reactivity (here: likelihood to be displaced following receipt of agonism), performance of social grooming and head butts, and the receipt of agonistic noncontact challenges  Cows with subclinical mastitis demonstrated altered feeding patterns:  Spent a greater proportion of feeding time in direct contact with 2 conspecifics, and a lower proportion of feeding time at self-locking feed barriers We conclude that changes in salivary SAA, social behavior, and activity offer potential in the detection of subclinical mastitis and recommend further investigation to substantiate and refine our findings.

Answer 292

Data generated from the AMS, such as milk yield, milk flow, conductivity, and online somatic cell counts, were used as input to 4 multilayer perceptron models to detect or predict single milkings with clots and to detect milking periods with clots. All models resulted in high specificity (98-100%), showing that the models correctly classified cow milkings or cow milking periods with no clots observed. The ability to successfully classify cow milkings or cow periods with observed clots had a low sensitivity.  Using data from AMS to detect and predict changes in milk homogeneity seems to be possible, although the prediction performance for the definitions of clots used in this study was poor.

Answer 293

 Cows that spend more time standing and engage in longer standing bouts in the weeks after calving were at increased risk of developing sole haemorrhages and sole ulcers later in lactation.

Answer 294

 Sensitivity varied by pathogen, with higher values observed when detecting IMI caused by Streptococcus uberis, Streptococcus dysgalactiae, Staphylococcus aureus, and Lactococcus lactis.  Negative predictive values were high for major pathogens among all algorithms (≥0.87), which may explain why algorithm-guided SDCT programs have been successfully implemented in field trials, despite poor agreement with overall IMI status.  Removal of clinical mastitis criteria for each algorithm had little effect on the algorithm classification of cows, indicating that algorithms based on SCC alone may have similar performance to those based on SCC and clinical mastitis criteria.  We recommend that producers implementing algorithm-guided SDCT use algorithm criteria that matches their relative aspirations:  For reducing antibiotic use (high specificity, positive predictive value)  For minimizing untreated IMI at dry-off (high sensitivity, negative predictive value).

Answer 295

 High contamination with environmental, fecal, skin, and mucosal microbes was found.  Only 28.4% of colostrum samples met the basic requirement for total plate count, and 88.2% met the basic requirement for total coliform count.  TPC: <100,000 cfu/mL  Total coliform count: <10,000 cfu/mL  Gram negative noncoliform count: <5,000 cfu/mL Our study showed high microbial contamination of colostrum collected on dairy farms. Therefore, better hygiene and sanitation around colostrum harvest should be addressed by farmers.

Answer 296

 The shorter the interval between administration of prepartum booster vaccination and calving, the lower the colostral IgG concentrations.  Vaccinating cows at 28 d prepartum, 7 d before pen change with an acidogenic diet, improved colostral IgG concentrations at calving and tended to reduce the rate of clinical mastitis within the first 150 DIM compared with cows immunized concurrent with a pen change at 21 d prepartum

Answer 297

 We found frequent associations with welfare outcome measures for the amount of milk delivered per cow (e.g., lower risk of very lean cows or dirty hind legs but higher risk of mastitis treatments or antibiotic dry-off with increasing milk delivery), housing system (e.g., loose-housed animals were at lower risk of lesions on the tarsal joint than animals kept in tiestalls, but at higher risk of being classified as very fat),  Beneficial associations were consistently found for an increasing number of days with access to pasture (e.g., body condition, integument alterations, lameness) as well as organic compared with conventional farming

Answer 298

 Reducing milking frequency to once daily without reducing the feeding level decreased milk yield before dry-off in high-yielding dairy cows and reduced udder engorgement after dry-off without inducing negative energy balance  Reduced feeding level induced negative energy balance, which may compromise welfare due to metabolic stress and hunger  No clear differences in risk of milk leakage after dry-off were observed between abrupt and gradual dry-off management strategies.  Use of cabergoline led to fewer signs of milk leakage and reduced udder engorgement during the first days after dry-off, which may positively affect welfare at dry-off.

Answer 299

 TUS and CRS scores were weakly correlated. The TUS was associated with reduced ADG.  Calves with TUS scores ≥3 grew at 126 g/d less than unaffected calves over the 3-wk period before examination.  The predicted effect on ADG was dependent on the age and duration over which the animal was affected  There was no association of CRS with ADG.  Weight gain was lowest in animals with consistently high TUS scores (i.e. in chronic cases) This study showed that in contrast to CRS, higher TUS scores are associated with lower ADG, with weight loss being more pronounced in chronic cases.

Answer 300

 Calves fed less milk consumed more starter during the preweaning and weaning periods, but a similar amount postweaning.  Both gradual weaning treatments resulted in similar feed consumption, growth, and health parameters.  Delaying a moderate increase in milk as “acclimatisation” until 12 d after arrival at a rearing facility provided no overall beneficial effect on growth or rumen development.

Answer 301

 Feeding rumen-protected Met did not affect pregnancy per AI or pregnancy loss measured at several time points after timed AI and did not affect other secondary outcomes, including uterine health, ovarian cyclicity, response to synchronization of ovulation, or embryo development and survival.

Answer 302

 Acrosome integrity and viability were the only sperm attributes that were significantly different between high- and low-fertility bulls

Answer 303

 Resting and rumination activity decreased to daily nadirs, whereas eating and high activity peaked at ooestrus.  Cows that returned to ooestrus after insemination had greater daily eating and high activity times and lower rumination and resting times during the expected time of oestrus on d 21 through 26 after insemination compared with pregnant cows and cows failing to return to ooestrus.

Answer 304

 Cows randomly assigned to two treatment groups, “offered” for voluntary consumption, mixed in 20L and offered within 3h of calving:  Ca supplement containing 45g Ca as well as dextrose and other components  Placebo incl. 20g dextrose.  81% cows voluntarily consumed the Ca supplement  No MY or composition differences for multiparous cows  Primiparous cows had increased MY and composition, decreased risk of subclinical ketosis, and increased calving interval. The supplementation of the tested oral Ca-energy solution at calving did not increase the probability to reach a next lactation for neither primiparous or multiparous, but positively influenced milk yield and milk component yields for primiparous.

Answer 305

 RPC tended to reduce the increase in RR, increased MY, reduced fatty acid and tryglyceride concentrations and increased revised insulin sensitivity.  Rumen-protected choline partially mitigated the effect of heat stress in mid-lactation cows

Answer 306

 Metabolizable energy for maintenance was 0.146 ± 0.0087 Mcal per unit of metabolic body weight (MBW).  Net energy for maintenance as determined via fasting heat production was 0.102 ± 0.0071 Mcal/MBW.  Net energy for maintenance estimated via regression was not different between lactating and dry cows; however, the efficiency of converting metabolizable energy into net energy was greater for dry compared with lactating cows (0.714 vs. 0.685) when evaluated with a fixed intercept

Answer 307

 Feeding calcium salts of palm fatty acids increased NDF digestibility, tended to increase FA digestibility, and increased the yields of milk, milk fat, and 3.5% FCM.  CSPF increased milk fat yield by increasing the yields of mixed and preformed milk FA.  There was a very small reduction in the content of milk protein, Feeding CSPF increased NDF digestibility, tended to increase FA digestibility, and increased the yields of milk, milk fat, and 3.5% FCM. Additionally, CSPF increased milk fat yield by increasing the yields of mixed and preformed milk FA.

Answer 308

 Holstein calves fed MR and starter supplemented with 0, 5, 10, or 15 mg/kg of BW mixed tocopherols daily from 2-3d until 56d of age.  Data suggests that tocopherols may improve an animal's oxidative status, directing more nutrients toward growth and improving animal efficiency. Further consideration should be given to the effects of these isoforms in diets of ruminants

Answer 309

 High dietary protein supplies increased milk yield and tended to increase postpartum dry matter intake  Controlled intake decreased postpartum body condition loss and serum β-hydroxybutyrate over the 9 weeks of lactation.  Feeding a prepartum high-protein diet combined with restricted intake can provide benefits of both strategies than relying independently on increased dietary protein or restricted intake.

Answer 310

 To evaluate the potential economic and environmental effects of the formulation model used to balance dairy rations for metabolizable protein (MP) or 3 essential AA (EAA: His, Lys, and Met)  Formulating based on AA has the potential to reduce pollution while enhancing net income

Answer 311

 Low to moderate heritability (0.06–0.45) was estimated for semen quality traits, indicating the possibility of improving these traits through selective breeding.  Positive moderate to high genetic correlations between semen quality and service sire non-return rate traits also indicated that selection for semen quality traits might be favorable for improving service sire NRR.

Answer 312

 Housing treatment did not affect calf health, performance, ability to learn to use the teat in the first 2 wk, or use of an autofeeder after grouping.  Following initial grouping and regrouping, previously pair-housed calves spent more time lying socially, but previous social contact did not affect interaction with novel pen resources or locomotor activities.

Answer 313

 We found no differences between treated and control cows in the incidence of reproductive tract diseases, mastitis, displaced abomasum, culling in early lactation, or in reproductive performance.  Cows that received pegbovigrastim produced approximately 1 kg/d less milk in early lactation.

Answer 314

 Neither of the 2 ELISA tests yielded satisfactory sensitivity without compromising specificity.  For Medicago's ELISA test, an Se (95% posterior credible interval) of 0.57 (0.32; 0.94) could be achieved without compromising Sp  For GD Animal Health's in-house ELISA test, an Se of 0.60 (0.37; 0.92) was achieved without compromising Sp.  Currently, inspection at trimming in a chute is necessary for surveillance of digital dermatitis in Norway, although these ELISA tests of bulk tank milk might be a useful supplement.

Answer 315

 Clot density was scored based on coverage of the filter area as 0 (negative), 1 (trace), 2 (mild), 3 (moderate), 4 (heavy), and 5 (very heavy).  QMS 3 could be a reasonable threshold for detecting quarters with abnormal milk that require further attention.  The risk for a cow having clots in milk increased with clots present in previous milking, longer milking interval, and lactation number, and decreased during lactation. Validated methods for assessing clots in individual udder quarters are essential for setting industrial standards and to develop technologies for detection

Answer 316

 Cows entering second parity had lower Brix values compared with cows entering third or greater parity  Prepartum vaccination of cows led to higher Brix values compared with nonvaccinated cows.  Cows with a moderate to high lameness score had lower Brix values than cows with low-grade lameness.  An increase of glutamate dehydrogenase serum activity and serum calcium concentration were associated with lower Brix values  An increase in the difference of total protein and albumin serum concentration led to higher Brix values.  In conclusion, the metabolic health of the cow affects colostrum quality and may cause failure of passive immunoglobulin transfer as well as impaired calf health

Answer 317

 Total milk consumption, the percentage of milk allotment consumed, drinking speed, and the number of unrewarded visits were all significantly associated with 2 or more of bovine respiratory disease, neonatal calf diarrhoea, or general disease.  Calves with BRD consumed 63% less of their daily allotment of milk, had 2 fewer unrewarded visits to the automated milk feeder, and drank milk 152 mL/min slower compared with calves without BRD.  Calves with NCD consumed 57% less of their daily milk allotment, consumed 758 mL less per day, and drank 92 mL/min slower than calves compared with calves without NCD. Calves with general disease drank 50% less of their daily milk allowance, consumed 496 mL less per day, drank 80 mL/min slower, and had 2 fewer unrewarded visits to the automated milk feeder, when compared with calves without disease.  The sensitivity of disease detection was low; thus, to increase it, parallel interpretation was completed. With parallel interpretation, the use of an automated milk feeder can be a useful preliminary tool in disease detection.  Parallel testing resulted in a sensitivity of 0.82, 0.78, and 0.84, and a specificity of 0.26, 0.23, and 0.21, for BRD, NCD, and general disease, respectively. This suggests that automated milk feeders may serve as a useful preliminary tool in the detection of diseased calves.

Answer 318

 All clinical stages of digital dermatitis were associated with increased foot skin temperature.  Feet with active lesions were recorded having higher mean interdigital skin temperature compared with feet with chronic, inactive digital dermatitis lesions and nonaffected feet.  IST was highest in feet with M2 lesions, followed by M1 and M4.1 lesions.  This method can be used precalving with a sensitivity of 0.88, and a specificity of 0.66

Answer 319

 Reducing feeding level, either before or on the dry-off day, resulted in consistently increased feeding motivation, interpreted as a sign of hunger.  No clear effects of change in milking frequency, singly or combined with reduced diet energy density, on feeding motivation were found.  The effects of cabergoline on feeding motivation are not easily interpreted and warrant further investigation.  From a hunger perspective, reducing milking frequency rather than diet energy density seems to be a less negative management to reduce milk production before dry-off.

Answer 320

 Free herds have lower SCC, culling risk, calf mortality rate, and shorter calving interval than the breakdown herds.  New BVDV introduction affected the SCC and CMR.  In the year after BVDV introduction, the SCC was higher than that in the year before BVDV introduction, with a factor of 1.011 [2.5th to 97.5th percentile (95% PCTL): 1.002, 1.020].  Compared with the year before BVDV breakdown, the CMR in the year of breakdown and the year after breakdown was higher, with factors of 1.170 (95% PCTL: 1.120; 1.218) and 1.096 (95% PCTL: 1.048; 1.153), respectively.  A new introduction of BVDV had a negative but on average relatively small effect on herd performance in herds participating in a BVDV control program.

Answer 321

 The average, maximum, and last cow-composite SCC of lactation were all predictive of presence of a major pathogen IMI and did not differ in their ability to discriminate infected from uninfected cows.  Optimal cut points for: * Last SCC: 108 × 1,000 cells/mL * Maximum SCC: 152 × 1,000 cells/mL * Average SCC: 105 × 1,000 cells/mL  Cow-composite SCC on its own resulted in sensitivities and specificities of between 0.76 and 0.86, and 0.71 to 0.80, respectively, for determination of presence of major pattern IMI, and the predictive value was not improved by addition of other predictor variables.

Answer 322

 Antimicrobial resistance was common in Staphylococcus epidermidis and Staphylococcus haemolyticus from all different groups, with resistance to trimethoprim-sulfonamide frequently occurring in Staph. epidermidis and Staph. haemolyticus as well as in Staph. aureus. Almost all Staph. aureus isolates were positive for at least 3 of the screened virulence genes, whereas, in total, only 8 NAS isolates harbored any of the same genes. Our study contributes to the continuous need for knowledge regarding staphylococci from food-producing animals as a basis for better understanding of occurrence of resistance and virulence traits in these bacteria.

Answer 323

 There were no effects of housing on calf health, feed intake, or average daily gain. The rebound effect of movement-related behaviors of INDI calves in a novel arena implies that individual housing of calves causes activity deprivation by the second week of age.

Answer 324

 No differences were found in number of treatments or recurrence risk of pneumonia or otitis  Both drugs used in the study were effective in reducing rectal temperature, ear scores, leukocyte counts, and mean relative abundance of the genera Mannheimia, Pasteurella, and Moraxella in the URT.  Neither were effective at reducing the mean relative abundance of Mycoplasma

Answer 325

 Precalving continuous-release monensin capsule administration affected postcalving milk fatty acid profile and the identification accuracy of most estimated FA for NEFA cows and some FA for HYK cows.  For all FA, the threshold values to identify NEFAH and HYK cows were different in the CO and MO groups. Specific milk fatty acid thresholds for identification of NEFA and HYK cows are applicable only within similar feeding conditions and rumen environment.

Answer 326

 Colostrum 10%BR then MR 10%BW  Colostrum 12%BR then MR 20%BW  20%-MR calves showed greater efficiency estimates preweaning, but this effect did not occur after weaning, suggesting that energy use efficiency does not persist until later stages in life.

Answer 327

Maternal DCAD did not affect colostrum IgG content fed to calves (P200 = 95.0 vs. N50 = 91.0 vs. N150 = 97.1 ± 4.1 g/L) or apparent efficiency of IgG absorption (P200 = 33.1 vs. N50 = 33.1 vs. N150 = 34.2 ± 1.9%). Males were born heavier than females, but maternal DCAD did not affect birth weight of all calves (P200 = 37.7 vs. N50 = 37.3 vs. N150 = 37.8 ± 0.7 kg) or daily weight gain in females in the first 56 d of life (P200 = 0.80 vs. N50 = 0.81 vs. N150 = 0.77 ± 0.03 kg/d). Treatment did not affect intake of milk (P200 = 1.11 vs. N50 = 1.04 vs. N150 = 1.19 ± 0.06 kg/d) or starter grain DM (P200 = 0.27 vs. N50 = 0.27 vs. N150 = 0.21 ± 0.06 kg/d), or measures of feed efficiency. Treatment did not affect concentrations of minerals in serum, morbidity, or age at morbidity. Manipulating the DCAD of pregnant nulliparous dams during late gestation did not affect offspring performance in the first 2 mo of age.

Answer 328

Preweaning urinary purine derivatives, preweaning microbial protein synthesis, and postweaning urinary nitrogen were greater for calves fed the 22CP diets than for those fed the 18CP diets but were not affected by the different RUP:RDP ratios. The concentrations of blood glucose and insulin were greater in 22% CP than in 18% CP diets. The blood insulin concentration was greater when calves received the HR diets compared with the LR diets. Growth performance was positively influenced by greater starter protein content because of increased microbial protein synthesis and blood insulin concentration.

Answer 329

 β-carotene supplementation did not affect colostrum quality or yield but increased the solids content of colostrum. Calves fed colostrum from cows supplemented with β-carotene had decreased apparent efficiency of absorption of immunoglobulin G but improved feed efficiency.

Answer 330

 Cows consuming alfalfa silage inoculated with L. plantarum MTD-1 tended to increase dry matter intake and increased milk production and organic matter truly digested in the rumen despite not improving yield of energy-corrected milk. Therefore, alfalfa silage treated with L. plantarum MTD-1 may improve ruminal fermentation and milk production; however, because of a lack of response in ruminal N metabolism, these changes did not result in greater energy-corrected milk in high-producing dairy cows.

Answer 331

 Compared to a dry period length of 51-60d  Dry period lengths shorter or longer than the conventional length of approximately 55 d were associated with slightly greater risks of culling

Answer 332

 During the preweaning period, addition of molasses to the mixed diet did not affect the extent of feed sorting  These results indicate that addition of molasses slightly reduced sorting during the postweaning period only.

Answer 333

 Leaving quarters untreated with intramammary antibiotic in cows in the high cell count group, with a CMT <2 or <1, reduced antibiotic use by 55% and 31%, respectively, and resulted in no difference in the odds of being infected with any pathogen postcalving, but was associated with a higher SCC at the first test day.  No differences in clinical mastitis incidence and milk yield in the first 100 d in milk were detected between any of the treatment groups.  These study findings support selective quarter level dry off treatment only in cows with cow level SCC >200,000 cells/mL at dry off.

Answer 334

 The increase in size of thick-walled veins in the teat tissue is the main reason for the thickening of the teat walls in response to machine milking.

Answer 335

 We did not find any significant association between precalving rumination time and disease within the first 30 DIM.  Higher rumination time in the week before calving was shown to be strongly linked to a shorter time to subsequent pregnancy, whereas rumination times postcalving were not associated with changes in the time to pregnancy.  A curvilinear combination of gestation length and duration in the close-up pen was significantly associated with changes in disease incidence in the first 30 DIM. Gestation length and time spent in close up are important management factors in reducing the incidence of disease in early lactation, and rumination times around calving may help predict future reproductive outcomes.

Answer 336

 Biplate – G+ve versus G-ve  Triplate - Streptococcus and Strep-like organisms, Staphylococcus, and gram-negative bacteria.  For CM and SCM, accuracy of the methods varied by causative pathogen  The results of chromogenic culture media may be useful for rapid decision-making on mastitis treatment protocols of the main mastitis-causing microorganisms, but their use for implementation of mastitis control measures will depend on each farm specific needs.

Answer 337

 Generally, the MIC of CNS and streptococcal isolates from organic herds were lower than isolates from herds using DCT. However, the differences in MIC distributions occurred at MIC below clinical breakpoints, so that the bacteriological cure rates may not differ

Answer 338

 Mirror scoring in a milking parlor or a pen without washing the feet was an easy way to score cows for digital dermatitis, but its sensitivity was relatively low, especially for active lesions. However, this method would be suitable for longitudinal monitoring and control of digital dermatitis within farms.

Answer 339

 Feeding RPM increased plasma Met concentration and improved lactation performance via increased milk protein production.

Answer 340

 Inoculation with LBB increased acetate concentration, reduced yeast counts and improved aerobic stability but did not improve dairy cow performance.  Inoculation with LBB increased acetate (62%), 1, 2 propanediol (364%) and propionate (30%) concentration and aerobic stability (73.8%) and reduced lactate concentration (7.2%), yeast counts (7-fold) and mold counts (3-fold).

Answer 341

 Generally, Palmitic acid tends to increase milk fat production with variable effects on dry matter intake, whereas stearic acid has minimal effects on DMI  Palmitic acid treatment had the lowest feed intake.  The palmitic acid and the palmitic and stearic acid blend both increased milk fat yield compared with the control diet.  The stearic acid treatment had the lowest fatty acid digestibility. In conclusion, supplementing PA increased milk fat yield compared with control and SA, but supplementing a mixture of PA and SA increased energy-corrected milk without decreasing intake. The FA profile of fat supplements influences their digestibility and effects on DMI and milk and milk fat synthesis.

Answer 342

 Elevated: 8L/day 5.41 MCal, 24% crude protein, 18% crude fat, and 45% lactose  Restricted: 4L/day , 2.71MCal, MR composition as above  Elevated group consumed more milk replacer, resulting in a lower starter intake and a greater body weight and average daily gain during the preweaning period  Differences in energy metabolism identified – elevated group associated with gluconeogenic nutrients via MR, whereas restricted group ketogenic nutrients via calf starter. The metabolic profile differences between the ELE and RES groups reflect the broad differences in nutrient intake and diet composition and might point to which metabolic processes are responsible for greater dairy performance for cows fed a greater milk supply preweaning.

Answer 343

 During the grower phase, initial BW was greater for ADLIB versus MOD, though final BW was not different between MOD and ADLIB or STEPUP.  Calves previously fed MOD had greater average daily gain, feed efficiency, and HW change than calves fed ADLIB.  Feed efficiency was lower when MR was fed ad libitum, and growth advantages observed at 2 mo were lost by 4 mo of age

Answer 344

 Physically effective neutral detergent fiber inclusive of particles >8 mm (peNDF >8) and dietary starch [% of dry matter (DM)] were sufficient for predicting daily mean ruminal pH  {y = 5.960 – (0.00781 × starch) + (0.03743 × peNDF >8) – [0.00061 × (peNDF >8 × peNDF >8)]}.  Time of pH suppression (<5.8 for ruminal pH or <6.0 for reticular pH, min/d) can be predicted with additionally including DMI (kg/d):  124.7 + (1.7007 × DMI) + (20.9270 × starch) + (0.2959 × peNDF >8) – [0.0437 × (DMI × starch × peNDF >8)].  As a rule of thumb, when taken separately, we propose 15 to 18% peNDF >8 as a safe range for diet formulation to prevent SARA, when starch or NFC levels are within 20 to 25% and 35 to 40% ranges, respectively.  At dietary starch content below 20% of DM, grain type was insignificant in affecting ruminal pH.  Increasing dietary starch contents by using corn as the sole grain source could lead to more severe drops of pH compared with using grain mix based on barley and wheat, as underlined by an interaction between starch content and grain type.  Data emphasized an increased risk of SARA for cows in the first and second lactation  Given that a lower ruminal pH is expected in these high-risk cows, it is advisable to keep the lower end of recommended starch (20%) and higher peNDF >8 (18%) contents in the diet of these cows. Overall, the present study underlines the possibility of predicting SARA based on dietary factors including peNDF >8 and starch contents, as well as DMI of the cows, which can be practically implemented for optimal diet formulation for dairy cows. With more data available, future studies should attempt to improve the predictions by including additional key dietary and cow factors in the models.

Answer 345

 There is a direct relationship between elevated somatic cell count (SCC) in an individual cow milk production and milk loss.  The traditional approach of using bulk tank somatic cell count (SCC) to estimate total herd milk loss due to subclinical SCC inaccurately assesses reductions in milk loss.  Estimates of total herd milk yield loss vary with the distribution of cow-level SCC and parity within the herd, so it is imperative that milk loss be calculated on a per cow basis and summed to calculate the total herd loss.

Answer 346

I. Significant losses in cumulative milk yield (−382 to −989 kg) and correspondingly lower fat and protein yields were found in mastitic cows, with transition and late-lactation mastitic cows having the highest losses II.? cows that had a first instance of mastitis at any of the 4 lactation stages had lower milk production than healthy cows * Transition: MY reduction of 8% * Early lactation: MY reduction of 6% * Mid lactation: MY reduction of 5% * Late lactation: MY reduction of 10% respectively, compared to their healthy counterparts that had the same prior production levels The research reflects the performance implications of mastitis, providing more information upon which the producer can make informed culling decisions and maximize both herd profitability and cow longevity.

Answer 347

 Cows experiencing an instance of lameness in any of the 4 investigated lactation stages experienced significant reductions in cumulative milk yield and milk components.  The largest reductions in milk yield were in transition lame cows, at 1,200 kg less over the course of their lactation compared with healthy cows

Answer 348

 At the herd level, feed push-up frequency (mean = 12.8 ± 8.3 times per day) and feed bunk space (mean = 64 ± 21.5 cm/cow) were positively associated with milk yield.  Herds with lower somatic cell counts had more frequent alley cleaning (mean = 12.1 ± 7.5 times per day), wider lying alleys (mean = 304.5 ± 40.0 cm), and sand bedding. The results highlight the importance of using sand bedding, using mechanical ventilation, keeping feed pushed up, ensuring alleys are clean, and ensuring adequate space at the feed bunk for maintaining herd-level productivity and milk quality in farms with AMS.

Answer 349

 The waiting period could be extended until 200 d for primiparous cows and until 125 d for multiparous cows without an effect on milk yield per day of calving interval.  The VWP could be extended from 50 d to 125 d without an effect on daily yield per day of calving interval.  Extending VWP until 200 d for primiparous cows did not affect their daily milk yield, but multiparous cows with a 200-d VWP had a reduced milk yield per day of calving interval and an increased body condition in late lactation and the subsequent lactation, compared with multiparous cows with a 50-d VWP.

Answer 350

 Changes in gene expression in the liver between normal and overconditioned cows revealed a relatively low number of differentially expressed genes. Some upregulated genes and pathways in overconditioned cows were associated with inflammation and immune response activation. Overconditioning at the end of pregnancy may alter the hepatic gene expression pattern to a proinflammatory state.

Answer 351

 Untreated calves had more diarrhoea and higher faecal scores  No impact on any other disease incidence  Growth performance, feed intake, and feed conversion ratio were not different.  The current study provides evidence that neomycin inclusion in milk replacer reduces fecal scores and the duration of diarrhoea in calves but does not improve other indicators of health or growth performance.

Answer 352

 Heifers diagnosed with calfhood BRD (up to 12months of age) had higher odds of dying and of herd removal before first calving compared with heifers never diagnosed with this condition.  Heifers with calfhood BRD also had a decreased average daily gain and produced less milk during their first lactation.

Answer 353

 Cows with a high albumin-to-globulin ratio (1 Vs 0.75) before dry-off experienced increased milk yield, better udder health, and improved fertility and were characterized by blood biomarkers as having a better overall inflammatory and metabolic condition than cows with a lower albumin-to-globulin ratio.  The AG ratio before dry-off might represent a rapid and useful proxy to evaluate the innate immune status

Answer 354

 Flow-controlled vacuum increased peak milk flowrate by 12% and increased average milk flowrate by 4%.  The decrease in individual cow milking duration was proportional to milk yield per milking.  Postmilking teat condition was good during the entire study period.  The occurrence of rough teat ends was slightly reduced during the flow-controlled vacuum period  The reduction in milking duration of individual cows allows a higher rotary parlor speed Model results showed that increased parlor throughput resulted in increased labor efficiency, reduced labor costs for milking, and a positive benefit-cost ratio on the investment for all but the smallest herd and parlor sizes considered.

Answer 355

 In multiparous cows, negative DCAD fed for 3 wk before calving improved serum calcium concentration postpartum and reduced the number of cows affected by multiple diseases within 30 d of parturition. Independent of parity, negative DCAD decreased incidence of displaced abomasum and tended to decrease incidence of clinical mastitis within 30 d after parturition but did not change the incidence of other diseases.

Answer 356

 The DTPA-IMB method used in combination with the rhodamine hydrazone immunosensor had a limit of detection equal to 30 and 30,000 MAP cells/mL using chromogenic and fluorescent properties, respectively.

Answer 357

 The cut-off level for PMN defined as CYTO was set to 3.0%, representing the level at which the PMN occurrence affected pregnancy outcome, with the highest summation of sensitivity (32.4%) and specificity (74.9%).  Prevalence of cytological endometritis was 28%  Pregnancy to first AI was lower in CYTO-positive cows (OR = 1.51) although overall, fertility was high  Late embryo loss not associated with cytologic endometritis Overall, our results suggest that even if Norwegian Red cows show a fairly high prevalence of CYTO in the endometrium at first AI, it does not seem to have a major effect on the reproductive performance. The Norwegian Red breeding program has emphasized fertility and health for decades, and a genetically advantageous uterine immunology might be one of the preserved mechanisms.

Answer 358

 Variables associated with a lower proportion of new high SCC on herd level during the dry period were: o The use of dip or spray after drying off o A higher animal-defined daily dose of intramammary antimicrobials for DCT o The use of DCT in low-SCC cows based on SCC or mastitis history o Correct knowledge of DCT guidelines o An awareness of importance of low infection rate and good hygiene during dry-off.  Variables associated with a higher proportion of new high SCC on herd level were: o Dry cow housing other than cubicles o A higher animal-defined daily dose for intramammary antimicrobials for mastitis.  Udder health during the dry period seems unaffected by the introduction of selective dry cow therapy. A high management standard and the ability to select suitable cows for dry cow therapy can compensate for a reduction in the use of these antimicrobials.

Answer 359

 Heifers with a history of BRD before weaning were less likely to be inseminated or achieve first calving than heifers without BRD. However, BRD status did not change the age at first insemination of calving among those being inseminated or reaching first calving, respectively  A history of diarrhoea preweaning was not associated with changes in the probability of being inseminated, having a confirmed pregnancy, or reaching first calving. However, heifers affected by diarrhoea required more inseminations to become pregnant. Diarrhoea status was also associated with a 325-kg reduction in 305ME in the first lactation and a 50 g/d reduction in ADG.

Answer 360

 The treatment of cephalosporins led to change in the milk microbiota and increase of β-lactam resistance gene in the milk at the time of withdrawal period. o Treatment associated with lowered bacterial diversity o Cephalosporin treatment increased the proportion of blaTEM in milk samples

Answer 361

 The volume of the digital cushion was negatively associated with the number of lameness events or CHL recorded.  Animals with body condition score >3, culled later in lactation, or of a greater body weight were more likely to have a higher volume of digital cushion in the lateral claws.

Answer 362

 Cows diagnosed with metritis that do not undergo clinical cure by 10 d of onset of antimicrobial therapy have impaired reproductive performance, reduced milk production, and increased risk of leaving the herd. o Failure of clinical cure associated with a smaller proportion of cyclic cows, reduced P/AI, greater pregnancy loss, reduced hazard of pregnancy by 300DIM and lower milk production for the first 10 months postpartum o In comparison, metritis that cured was associated with reduced MY for 2 months pp

Answer 363

 Based on our results, the current literature lacks a clear repeatable clinical definition of infectious respiratory disease in adult dairy cows.  The most commonly reported clinical signs were fever (without specifying a precise temperature threshold), nasal discharge, cough, and dyspnea.

Answer 364

 Animals increased their distance from other cows beginning approximately 4 h before calving  If available, animals separated further from herd mates during the 4hrs precalving  More animals calved in the area of the pen that contained a blind compared with the same respective areas of high and low stocking density pens that did not contain a blind.  Increased space and a blind may allow cows to perform natural behaviours before calving.  Presence of a blind reduced attention from other cows around calving  Animals in pens with a blind had shorter labor lengths than those without a blind

Answer 365

 Quadratic associations between days on the close-up diet and the risk of uterine diseases and energy-corrected milk yield were detected, with 28 d on the close-up diet resulting in lowest incidence of disease and greatest milk yield.

Answer 366

 Following a reduction in milk intake of 20% or drinking speed of 30% during 14-50d of age calves fed either MR or 125g/d colostrum replacer  Calves fed a preventative dose of colostrum replacer, versus a placebo, were less likely to develop pneumonia 14 d later, but this treatment did not affect growth.  No difference was found for risk of diarrhoea  CR may reduce BRD likelihood but did not influence growth in calves offered high allowances of milk

Answer 367

 Daily milk consumption, drinking speed, and rewarded and unrewarded visits may provide insight into early disease detection in preweaned dairy calves

Answer 368

 An automatic spray on the upper surface of the brush motor with disinfectant along with daily change of brushes collectively reduced transmission of Strep. agalactiae and Strep. dysgalactiae

Answer 369

 Fusobacteria was numerically more abundant in the diarrheic group, whereas Proteobacteria and Actinobacteria were numerically more abundant in the nondiarrheic group.  Clostridium and Peptostreptococcus were more abundant in the diarrheic calves  Commensal bacteria acquired in the neonatal period may have been replaced with potential pathogens in diarrheic calves, which may have contributed to the incidence of diarrhoea either directly or indirectly.

Answer 370

 Cows with improved energy balance in early lactation had a shorter interval to start of luteal activity, greater milk progesterone concentrations at start of luteal activity, and earlier first observed heats.  Early-lactation energy balance did not affect conception rate to first service.

Answer 371

 Despite passing routine laboratory tests of semen quality, bulls used in artificial insemination exhibit a significant range in field fertility. Using Holstein Friesian bulls exhibiting extremes in fertility typical of those in artificial insemination, we report that although differences in field fertility were not reflected in fertilization rate, differences in embryo quality were apparent as early as d 7. These differences were reflected in a higher proportion of conceptuses surviving to d 15 in high-fertility bulls, which coincides with the period of maternal recognition of pregnancy in cattle.

Answer 372

 Final BW (84 d) did not differ between treatments.  Overall, calves fed ad libitum seemed to regulate their intake of MR based on its energy density, without significant effects on solid feed intake and overall growth

Answer 373

 High protein feeding, and methionine supplementation was associated with higher DMI  Higher protein feeding associated with increased milk yield.  Methionine supplementation increased milk fat and total solids concentrations. The data indicate that dairy cows around calving respond positively to an increase in the supply of MP and to rumen-protected methionine supplementation of the HP diet by increasing intake and improving immune status.

Answer 374

 Increasing peNDF8.0 concentration in high-concentrate diets could help alleviate subacute ruminal acidosis by increasing peNDF8.0 intake, chewing activity, and rumen pH. Feed digestibility and plasma metabolites were also enhanced

Answer 375

 Protocol: all calves with an increase of 0.5°C in rectal temperature compared with the previous week's measurement were treated for Anaplasma spp. and Babesia spp  Over half of treated cases were negative on blood smears  An optimized protocol would consider rectal temperature and smear results prior to treatment; which would be more economically viable.

Answer 376

 Culture and algorithm based SDCT approaches associated with financial savings  The extent of financial savings was reduced if clinical or subclinical mastitis frequency increased after SDCT

Answer 377

 Based on this study, assessments performed at 3 DIM using tCa concentration ≤1.99 mmol/L for increased risk of early-lactation culling and FFA ≥0.43 mmol/L for increased risk of metritis could be used as starting points

Answer 378

 Calves sedated with xylazine for cautery disbudding responded less to painful stimuli both during and following the procedure and had a higher rate of play behaviour 24 h following sedation compared with the nonsedated calves, but xylazine may also have a prolonged carryover effect that affects suckling behaviour for 48 h following sedation.

Answer 379

 Average rumination time and change in rumination time over the first 6 d in milk are associated with peak milk yield for multiparous cows, whereas no association was found for primiparous cows

Answer 380

 Cows that developed lameness in early lactation showed reduced daily rumination time in the period between +1 and +3 d relative to dry-off.  Cows that developed lameness in the first 60 d in milk showed reduced RT from 1 to 3 d following dry off compared with cows that were not diagnosed with lameness in early lactation.  Rumination time around dry off was not associated with the occurrence of mastitis, metritis, retained placenta, hyperketonemia, hypocalcemia, pneumonia, and displaced abomasum

Answer 381

 Sound of cows walking recorded, machine learning used to predict lameness.  This model obtained a sensitivity of 0.81 and a specificity of 0.97.  This study shows that lameness can be detected by machine learning from the impact sound of hoofs in dairy cows.

Answer 382

 Exposure to fine (PM1.0μm) particulate matter fractions was associated with increased odds of lung consolidations of ≥1 cm (OR: 3.3), ≥3 cm (OR: 2.8), and ≥6 cm (OR: 12.3).  The odds of having lung consolidations of ≥1 cm (OR: 13.9) and ≥3 cm (OR: 6.7) were higher when endotoxin concentrations in the dust mass exceeded 8.5 EU/µg.  Broncho-alveolar lavage fluid neutrophil percentage was positively associated with PM10 concentration  Concentration of particulate matter 2.5μm was positively associated with epithelial cell percentage and isolation of Pasteurella multocida.  In this study particulate matter fractions were associated with pneumonia in calves.

Answer 383

 An interaction between DPG as a quadratic covariate and parity-diet was observed for milk yield by 300 d postpartum. Means were 9,331; 9,665; and 9,261 kg for 7, 28, or 42 DPG, respectively, in nulliparous cows, and 9,886; 10,939; and 10,117 kg for 7, 28, or 42 DPG, respectively, in parous cows.  Morbidity affected 49.5, 52.9, and 59.5% of nulliparous and 49.7, 26.5, and 47.4% of parous cows that spent 7, 28, or 42 DPG, respectively.  A linear association between DPG and pregnancy at first artificial insemination was observed with estimates of 37.0, 32.6, and 29.8% for 7, 28, and 42 DPG  A quadratic association was observed between DPG and the proportion of pregnant cows at 300 d postpartum, and estimates for 7, 28, and 42 DPG were, respectively, 71.7, 73.5, and 58.8%  A quadratic relationship was also observed for DPG and removal from the herd by 300 d postpartum, and estimates were 25.2, 22.9, and 34.4% for 7, 28, or 42 DPG. For several responses evaluated, a quadratic association was observed, which suggested that there was an optimal period for cows to spend in the prepartum group, and reduced or extended number of days were detrimental to performance.

Answer 384

 Culling infected cows early in lactation may facilitate herd-level eradication of Strep. Agalactiae  A higher proportion of culling due to mastitis within 100 d from calving was associated with a higher probability of herd-level recovery from Strep. agalactiae in herds with conventional milking system.

Answer 385

 Most Strep. uberis and L. lactis were susceptible to all antibiotics tested.  Enterococcus faecium had consistently the highest minimum inhibitory concentration required to inhibit the growth of 90% of tested isolates.  Penicillin should remain the first-choice antimicrobial for the therapy of Strep. uberis and Lactococcus spp. However, a success of any antimicrobial treatment of enterococcal infections seems questionable.

Answer 386

 Ear tag based smartbow system applied to calves after birth  Lying and activity times the day before diarrhoea were associated with the odds of diarrhoea occurring the subsequent day

Answer 387

 Udder health deteriorations around the transition to an AMS were still observed, although less than historically measured.

Answer 388

 Udder cleanliness scored using a system of 1-4 derived by Schreiner and Ruegg, 2002  Herd udder hygiene assessed at milking was positively associated with clinical mastitis  At least 80 cows needed to be scored to achieve sufficiently precise estimations of herd udder hygiene  Cows scored later during the milking order were more likely to have poorer udder cleanliness.

Answer 389

 Aseptic quarter level samples taken from cows approaching dry off and cows followed until 120DIM  The presence of late-lactation IMI caused by major pathogens was positively associated with postcalving clinical mastitis  IMI caused by Streptococcus and Streptococcus (Strep)-like organisms, other than Aerococcus spp. (i.e., Enterococcus, Lactococcus, and Streptococcus spp.) were associated with increases in postcalving clinical and subclinical mastitis.  But infection with NAS species associated with variable effects, i.e. some species increase SCM and CM No associations were detected between IMI in late lactation and risk for postcalving removal from the herd within the first 120 DIM. Effect estimates reported in this study may be less than the underlying quarter-level effect size for IMI at dry-off and postcalving clinical and subclinical mastitis, because of the use of late-lactation IMI as a proxy for IMI at dry-off and the use of cow-level exposure and outcome measurements.  IMI associated with reductions in 120d MY. We conclude that IMI in late lactation may increase risk of clinical and subclinical mastitis in the subsequent lactation. The relationship between IMI and postcalving health and productivity is likely to vary among pathogens, with Staphylococcus aureus, Streptococcus spp., Enterococcus spp., and Lactococcus spp. being the most important pathogens identified in the current study.

Answer 390

 Pairs with Braden bottles and buckets approached starter sooner than those with only buckets  Cross sucking occurred for at least twice as long in pairs with buckets only  Regardless of starter treatment, calves spent less time cross sucking when fed milk in teat buckets  When calves are fed milk in open buckets, a novel option for reducing cross sucking is to provide starter through a specialized bottle. Nonetheless, providing milk in slow-flow teat buckets had the greatest effect on reducing cross sucking by directing suckling to the teat instead of another calf or pen objects.

Answer 391

 Infection status at parturition does not markedly affect colostrum antibody concentrations and quality  In Holsteins, concentrations of IgG1, IgG2, and IgA were greater in multiparous cows than primiparous cows; but this was not true for jersey cows

Answer 392

 Pairwise scoring consists of identifying the relative rank (i.e. which one is more lame) between two individuals  Pairwise scoring and scaling had the scoring consistency of binary absolute scoring with finer continuous granularity than 4-level absolute scoring. The pairwise scoring method, and associated scaling, offer a more consistent and informative alternative to conventional absolute multilevel locomotion scoring.

Answer 393

 Animals with a BCS of 3.00 or higher had a significantly increased cell size in comparison to those with a score of less than 2.50  The fatty acid esters C10:0 capric acid, C14:0 myristic acid, C15:0 pentadecanoic acid, and C20:0 arachidic acid percentages were all lesser in lower body condition score cows  Saturated fatty acid, monounsaturated fatty acid, and polyunsaturated fatty acid percentages were not altered in the different claws, ages, or body condition score groups Digital cushion anatomy, cellular morphology, and fatty acid composition have been described in general and also in animals with differing ages, body condition scores, and in the differing claws. Understanding fat deposition, mobilization, and composition are essential in not only understanding the roles that the digital cushion plays but also in preventing disorders and maintaining cattle health and welfare.

Answer 394

 Peak activity was associated with P/AI, with 1.35 greater odds of pregnancy for cows with high PA compared with cows with low PA  Increased THI 1 wk before AI was associated with shorter duration of oestrus, lower peak of activity, and decreased P/AI.

Answer 395

 Calves fed the concentrates only had lower DMI and ADG than the other two groups  There were no performance differences between calves fed the hay + concentrate separately or mixed  Calves fed the mixed ration developed a higher degree of sorting against long fractions, which persisted in the short term during TMR feeding  By the end of the experiment (wk 28), feed sorting and rumen pH were similar across all treatments.

Answer 396

 Failing to pasteurize nonsaleable milk and colostrum had a detrimental influence on performance of heifers with low birth weight, which remained apparent for more than 2 yr.  For the first 42 d of life, low birth weight heifers fed pasteurized versus raw NSM had greater weight gain, grain intake, and feed efficiency and were weaned earlier  During the first lactation low birth weight heifers fed raw nonsaleable milk produced less milk, MP, MF compared to those fed pasteurized NSM or MR. These findings confirm that calf management practices influence future performance; in this case, failing to pasteurize milk and colostrum for low birth weight heifers had effects that remained apparent for more than 2 years.

Answer 397

 daughters born from dams with elevated SCS had poorer performance.  Dam mean SCS was positively associated with daughter's AFC and first- and second-lactation mean SCS. Furthermore, for every 1-unit increase in dam mean SCS, daughter's first- and second-lactation mature-equivalent fat yield declined by 0.34% and 0.91% (−1.6 ± 0.49 kg, −4.0 ± 1.0 kg, respectively).  The association of greater dam mean SCS with lesser daughter milk fat yield is likely due to a few underlying mechanisms, in particular, a predisposition for mastitis and alterations in the epigenome controlling milk fat synthesis

Answer 398

 Healthy cows:  Took 1,613 ± 38 steps  Spent 181 ± 7.1 min at the feed bunk = 3hrs  Had 8.3 ± 0.17 meals  Had 9.8 ± 0.32 lying bouts  Spent 742 ± 11.3 min lying per day = 12.5hrs  Prepartum behaviour of cows affected with metritis, DA, and ketosis was different from that of cows not diagnosed with diseases during the 1wk prepartum:  Cows with metritis had more lying bouts (+21%)  Cows with DA had fewer meals (−24%) and tended to take fewer steps (−18%)  Cows with ketosis had fewer meals (−22%) and spent less time at the feed bunk (−40 Prepartum behavior of cows affected with metritis, DA, and ketosis was different from that of cows not diagnosed with diseases. Prediction equations were able to classify cows at high or low risk of ketosis and DA and can be used in taking management decisions, but the high false discovery rates requires further refinement.

Answer 399

 Five key themes emerged from the data:  Knowledge and awareness of antimicrobial resistance  Factors influencing farmer and veterinarian decision-making  Perceived barriers and facilitators to reduced antimicrobial use  Perceived responsibility for antimicrobial resistance  The role of the farmer and veterinarian relationship in reducing antimicrobial use. This review provided a coherent picture of what is currently known and identified gaps in the current knowledge to inform future behavioral intervention research. Increased knowledge, skill development, resources, engagement, and further research to address the gaps we identified are the main recommendations to effectively overcome barriers, elicit appropriate behavior change, and achieve reduced antimicrobial use in dairy cattle.

Answer 400

 Farms were selected based on the detection of methicillin-resistant Staphylococcus aureus (MRSA) during previous diagnostic investigations.  Methicillin-resistant NAS were detected on all study farms.  Nine MR-NAS species were identified; Staph. sciuri, Staph. lentus, Staph. fleurettii, Staph. epidermidis, and Staph. haemolyticus were the most common species.  Resistance genes may be transferred between NAS and Staph. aureus on the respective farms. On some farms, similar mobile genetic elements were detected in MR-NAS and MRSA. It was suggested that resistance genes may be transferred between NAS and Staph. aureus on the respective farms.

Answer 401

 2 on-farm tests used: CHROMagar Mastitis or Minnesota easy culture Tri-plate which discriminated gram positive, gram negative and culture negative.  Clinical cure rate, percentage of new IMI, and SCC on d 21 of clinical mastitis were comparable among the groups – using on farm kits led to more treatments in accordance with the aetiology of mastitis by farmers  For subclinical mastitis, antimicrobial usage was much higher in cases using either culture system than the controls  For subclinical mastitis, on-farm testing may lead to an unacceptable increase in use of antimicrobials and thus should not be advised as the common approach.

Answer 402

 The BCS at dry-off was associated with changes in feeding behaviour, such that overconditioned cows had lesser daily DMI and feeding time during the early and late dry periods compared with not overconditioned animals.  We also noted an effect of previous 305-d milk yield on DMI; cows that produced more milk had greater DMI throughout the dry period. The ΔBCS was only partially mediated by DMI, and BCS at dry-off still had a direct effect on ΔBCS. This result indicated that mechanisms other than DMI were associated with BCS loss during the dry period.  Strategies to improve intake during the dry period should take dry-off BCS into account or, preferably, efforts should be made to minimize the number of overconditioned cows at the end of lactation.

Answer 403

 There was higher DMI and milk yield in cows that remained normocalcemic or experienced a transient reduction in plasma calcium following calving. o No differences in prepartum feed intakes o Normocalcaemic and transient SCH cows consumed more feed than the pSCH or the dSCH during the first 3wk of lactation

Answer 404

 Using a threshold of <23% for digital Brix refractometer and <50 g/L for RID and TIR spectroscopy, median Se estimates were  23% Brix - 73.2  <50g/L RID - 86.2  <50g/L TIR - 91.9%  Median Sp estimates were  23% Brix – 85.2  <50g/L RID – 99.4  <50g/L TIR – 90.7%  A suggested Brix threshold of >23% could reduce feeding of low-quality colostrum to calves  TIR spectroscopy showed high Se in detection of low-quality colostrum.  The RID assay, which is used as the reference test in several studies, showed limited Se for detection of low-quality colostrum.

Answer 405

 Waste bins on farms for 12 months compared to farm medicine records and vet sales data  Although no method was perfect, by comparing the results of veterinary sales data, on-farm medicine records, and on-farm medicine waste bins, we concluded that veterinary sales data agreed best with the reference method used

Answer 406

 When using a dose-based metric, intramammary antimicrobials represented the greatest proportion of antimicrobials used, whereas using a mass-based metric, systemic antimicrobials represented the greatest proportion of antimicrobials used.  These results showed that choice of metric can substantially alter interpretations about quantities and routes of antimicrobials administered on dairy farms.

Answer 407

 Compared with sound cows, daily eating time differed by –20 min and –38 min for moderately (Score 3/5) and severely lame (score 4 or 5/5) cows, respectively.  Lame cows also lied down for longer and walked less steps  A loss in body condition during early lactation was associated with increased lameness postpartum in multiparous cows.

Answer 408

 Higher system vacuum caused faster milk removal in all liner and ventilation types.  Round liners milked faster than triangular liners at simultaneously lower mouthpiece chamber vacuum.  Mouthpiece chamber ventilation caused lower mouthpiece chamber vacuum with stronger fluctuations compared with claw ventilation in both liner types.  However, milking performance was not affected by the type of cluster ventilation Despite the observed differences of MPC vacuum, the ventilation type did not affect milking performance. However, milking with triangular MPC-ventilated liners caused an increased proportion of foamed milk, which could potentially have a negative effect on milk quality.

Answer 409

 The rYidR vaccine reduced the risk of CM caused by Klebsiella spp. and the mortality or culling of cows with CM caused by E. coli.  Additionally, cows immunized with rYidR produced more milk and had higher conception risk at the first service compared with cows injected with a placebo or a commercially available vaccine.

Answer 410

 After foot trimming, medial forelimb claw carried 70% of the entire forelimb load, with the palmar zone bearing 54% of the entire load and the greatest forces/pressures.  3mm plywood plates attached to the lateral claw only resulted in a more even load distribution  Equal load distribution between the forelimb claws was achieved in our setting when the lateral claws were left 3 mm higher than the medial claws.

Answer 411

 Whilst M. bovis was the most common, 21% of mastitis cases contained other Mycoplasma spp.  Our results suggest that it is critical to test milk samples for mycoplasmas using diagnostic tests able to identify both the genus and the species

Answer 412

 Differential somatic cell count represents the combined proportions of polymorphonuclear neutrophils plus lymphocytes (PMN-LYM) in the total somatic cell count (SCC).  Differential somatic cell count was also positively associated with the recovery of milk nutrients in the curd (protein, fat, and energy), which increased linearly with increasing DSCC The PMN-LYM count was rarely associated with milk traits, even though the pattern observed confirmed the results obtained when both SCS and DSCC were included in the model. The MAC count, however, showed the opposite pattern: MY, casein index, and lactose percentage decreased and milk conductivity increased with an increasing MAC count. No significant association was found between PMN-LYM count and MCP, CF, CY, and REC traits, whereas MAC count was unfavorably associated with MCP, CF traits, some CY traits, and all REC traits. Our results showed that the combined information derived from SCS and DSCC might be useful to monitor milk quality and cheesemaking-related traits.

Answer 413

 We showed that the pedal bone was sinking from 10 d before to 5 d after calving.  Solar thickness decreased when measured precalving and postcalving, associated with rotation of the distal phalanx toward the posterior part of the sole horn in the weeks around calving  There was NO correlation between BCS and solar soft tissue thickness. However, the heifers experienced many changes related to management, feeding, and time budget during the study period, and the rotation of the distal phalanx and reduction of the STT might be explained not only by calving but also by other factors that affect heifers and their claws during the transition period.

Answer 414

 Factors associated with a low SCC in primiparous cows included:  Having an SOP for colostrum feeding  Lower mean bulk SCC  Lower overall culling rate due to udder health  Not using automatic milking In conclusion, we identified several success factors for herds with good udder health among early lactation primiparous cows. This knowledge can be used to improve preventive measures in dairy herds to ensure sustainable and economic milk production.

Answer 415

 Majority of isolates belonged to the clonal complex CC103  Most isolates were susceptible to β-lactams

Answer 416

 Increased odds of adequate transfer of passive immunity associated with:  Calves receiving ≥2.5 L colostrum at their first meal  Calves receiving colostrum with ≥24.5% Brix  Calves receiving colostrum within 3 h after birth  Total bacteria count and TCC were not associated with the odds of adequate transfer of passive immunity

Answer 417

 The prevalence of adequate TPI was associated with the prevalence of an adequate colostrum volume fed at first meal (≥2.5L) and the prevalence of an adequate time to first feeding (≤3 h).

Answer 418

 Focused lung ultrasound only considers lung lobes most commonly affected by BRD:  The caudal aspect of the cranial lobe of the left lung (fifth and fourth left intercostal spaces; ICS)  The middle lobe of the right lung (fifth right ICS)  The caudal aspect of the cranial lobe of the right lung (fourth right ICS).  Pneumonia was diagnosed when a calf had a minimum of one small lobular lung lesion that was at least 1 cm deep within a normally aerated lobe  FLUS had a sensitivity of 81.6% and a Sp of 100%.  Flus might be of use when examining large numbers of calves, agreeing well with TUS

Answer 419

 Three OFC systems:  Minnesota Easy Culture System II Bi-plate (gram-positive, gram-negative)  Minnesota Easy Culture System II Tri-plate (gram-positive, gram-negative, some genus level)  FERA Diagnostics and Biologicals AccuMast plate (genus level, some species level)  all 3 OFC appeared suitable to support pathogen-based mastitis management when operated by trained observers.  Training beyond the instruction manual is a prerequisite to make OFC systems useful for pathogen-based mastitis management.

Answer 420

 Compared to SCC thresholds the DSCC was highly specific but moderately (50-75%) sensitive based upon SCC threshold (200,000 or 400,000 cells/ml).

Answer 421

 The majority of calf milk replacers contain more lactose and less fat than whole milk.  This study evaluated the effects of partially replacing lactose in milk replacer with fat on glucose metabolism in neonatal dairy calves.  This resulted in increased body weight gain during the first week of life, and although fasting insulin sensitivity was unaffected, smaller fluctuations in postprandial plasma glucose and insulin were observed and postprandial insulin sensitivity tended to be increased

Answer 422

 The accuracy of PAG may be compromised by cows undergoing pregnancy loss.  PAG not suitably accurate to determine a threshold for pregnancy loss or twins  Pregnancy loss and twins were predicted with moderate accuracy by P4 concentration at d 37 post-AI:  A threshold of 6.5 ng/mL predicted pregnancy loss with an area under the curve (AUC) of 0.64,  A threshold of 7.2 ng/mL predicted twins with AUC of 0.71. n summary, pregnancy loss and twins were predicted with only moderate accuracy by P4 concentration at d 37 post-AI, and the variability in PAG concentrations at d 37 post-AI was not sufficient to generate a threshold to predict pregnancy loss and twins in Holstein lactating cows.

Answer 423

 Previous parity milk production was associated with an increased probability of twin births across parity and breed.  Third and greater parity (3+) compared with second parity (2) and all breeds compared with Jerseys were associated with greater twin probability  Twin births associated with a lower hazard of subsequent pregnancy

Answer 424

 Cows with access to solar shade had similar behaviour characteristics, fly counts, and milk production compared with cows with no access to shade.  Shade cows had lower body temperatures and respiration rates between milking’s at the hottest parts of the day  Incorporating solar photovoltaic into pasture dairy systems may reduce intensity of heat stress in cows.

Answer 425

 Most survey respondents believed that antibiotic use in cows on dairy farms posed a threat to human health and indicated they would be willing to pay more for milk produced from cows raised without antibiotics.

Answer 426

 Monesin or not monesin bolused, two different dry cow strategies, monesin fed during lactation:  CE = Controlled energy diet throughout the DP  CU = controlled-energy diet from dry-off to 22 d before expected parturition, followed by a moderate-energy close-up diet from d 21 before expected parturition through parturition  Diet had little effect on subsequent lactation performance:  Milk fat and lactose content were greater for cows fed CU than for those fed CE  Lactose content and yield were increased for cows supplemented with MON.

Answer 427

 Unprotected choline chloride was fed at 2 neutral detergent fiber concentrations: 30 and 40%.  Unprotected choline chloride increased propionate molar proportion in diets with 30% neutral detergent fiber in which a greater starch content was available, allowing for a greater proportion of propionate. Our data indicate that unprotected choline chloride effects on ruminal fermentation depend on dietary NDF concentration, allowing for a greater propionate synthesis without decreasing organic matter disappearance when fed with a 30% NDF diet.

Answer 428

 Compared this conventional approach with a feeding protocol that supplemented the diet with chopped straw, diluting the energy density and increasing the physically effective fibre.  Adding straw to the diet of lactating cows reduced feed intake and milk yield and increased the incidence of subclinical ketosis during early lactation.

Answer 429

 4 treatment groups:  Control: diet not supplemented with fatty acids (FA)  Diet supplemented with a FA blend containing 80% C16:0 and 10% cis-9 C18:1 (80:10)  Diet supplemented with a FA blend containing 70% C16:0 and 20% cis-9 C18:1 (70:20)  Diet supplemented with a FA blend containing 60% C16:0 and 30% cis-9 C18:1 (60:30)  FA-supplemented diets increased milk fat content, milk fat yield,, tended to increase MP yield and MY.  Increasing cis-9 C18:1 in the FA supplement increased DMI and reduced BW and BCS losses  The fat-supplemented diets fed during the immediate postpartum period had a positive carryover effect during early lactation, when cows were fed a common diet. Our results indicate that feeding FA supplements containing C16:0 and cis-9 C18:1 during the immediate postpartum period increased nutrient digestibility, energy intake, and milk energy output compared with a non-fat-supplemented control diet. Increasing dietary cis-9 C18:1 increased energy intake, reduced markers of body fat mobilization, and improved energy balance during the immediate postpartum.

Answer 430

 Feeding a starter with higher crude protein increased growth of the reticulorumen and liver without affecting empty body weight gain.  Feeding the larger amount of milk replacer with the lower protein starter increased fat content of empty body weight gain after weaning, but the higher crude protein starter resulted in less fat in gain. A high-CP starter had minimal effect on empty BW gain before weaning, but after weaning it tended to increase mass of reticulorumen and liver.

Answer 431

was estimated that approximately 1% of gross milk revenue, equivalent to US$33 per cow, is lost annually in MAP-infected dairy herds, with those losses primarily driven by reduced production

Answer 432

 Milk yield and proportion of cows pregnant were lesser for cows with metritis than for cows without metritis  The proportion of cows leaving the herd was greater for cows with metritis than for cows without metritis.  The mean cost of a case of metritis was $513  Main costs were associated with decreased milk production, reproduction, and survival in the herd.

Answer 433

 The profitability of sexed semen was primarily dependent on the baseline fertility of the herd, as well as calf prices

Answer 434

 Increased RID-IgG1 levels in calf serum were associated with improved survival, as well as better early growth and fewer health problems  Heritability estimates were low to moderate, with the highest being for RID-IgG1 in colostrum (h2 = 0.28) and serum (h2 = 0.36).  Despite generally higher concentrations in beef than in dairy cattle, calves with low immunoglobulin levels existed, and negative effects on survival and subsequent performance were observed.

Answer 435

 In 31 animals the sensor was removed because the tail was swollen or painful.  Depending on the interval preceding the onset of parturition, sensitivity varied from 19 to 75% and specificity from 63 to 96%.

Answer 436

 Streptococcus uberis, followed by Streptococcus dysgalactiae, were the main causes of gram-positive CM.  The 2d protocol had similar bacteriological/clinical cures the 5d protocol  5d protocols were more effective at reducing milk cfu counts  Antibiotic use remains an indispensable strategy for treatment of CM caused by gram-positive bacteria.

Answer 437

 (I) We tested 4 tie-rail positions, including 2 novel tie-rail placements, and found that injury prevalence changed based on the location of the tie-rail. Overall, our results show that dairy cows are limited in their ability to move within their environment without coming in contact with the stall confines (tie-rail and divider bars), warranting further research to determine alternatives to metal tie-rail bars, such as a flexible bar or chain, or provide fewer obstacles through the elimination of some stall hardware.  (II) Compared the effect of a tie chain longer than the current recommendation on the ease of movement of dairy cows housed in tiestalls  Increasing chain length leads cows to modify the way they use the available space and improves their ease of movement upon lying down.  Increasing chain length could be implemented as a low-cost modification on tiestall dairy farms as part of a series of measures aiming to improve comfort of dairy cow at their stalls.  (III) Compared the effect of housing lactating dairy cows in tiestalls of double width compared with the current recommendation  Increasing stall width improves the cows’ comfort and resting capacity by providing them with increased opportunities to express and switch between natural lying postures.  Increasing stall width also reduced the prevalence of contacts with the stall elements during lying-down movements,  (IV) Tested the effect of stall length and manger wall height on dairy cows housed in deep-bedded tiestalls.  Increasing stall length increased lying time and allowed for healing of pre-existing injuries. Manger wall height may play a role in how the cow positions herself in the stall.

Answer 438

 pneumonia was defined as having lobar pneumonia, as diagnosed by US, in at least 1 lung lobe.  Severity of pneumonia was associated with an increased relative abundance of Pasteurella spp. in the nasopharynx.  Increased microbial diversity of the nasopharynx may be associated with reduced prevalence of clinical BRD

Answer 439

 Both SCC and DSCC increased after IMI, with a more pronounced increase if major or other pathogens were detected compared with minor pathogens.  Major pathogens had the longest-lasting effect in both herds for both SCC and DSCC.

Answer 440

 On average, for cows that did recover, the inflammation indicators recovered within 3 to 4 wk after the initial udder inflammation  A cutoff point between nonchronic and chronic changes in indicators of 3 to 4 wk after the initial inflammation for SCC and σ-conductivity is suggested

Answer 441

 cows preferred familiar individuals as grooming partners and feeding neighbors directly after regrouping and 1wk later  Familiar cows displaced each other at the feed bunk more than unfamiliar ones, possibly because they were neighbors more often  A small group of familiar cows may provide ongoing social buffering after regrouping.

Answer 442

 Calves raised individually or in pairs up until 16wks of age.  Pair raised calves were heavier at weaning and gained 150g/d more per day than the individually reared calves  During weaning pair raised calves had increased lying times. Our study demonstrated benefits, such as better growth and increased lying time, of pair housing calves during the preweaning period.

Answer 443

 Sheltered cows were cleaner, spent more time lying down, and showed fewer signs of fat mobilization than cows without access to shelter during the prepartum period (lower NEFA and haptoglobin precalving and postcalving respectively).  The provision of shelter mitigates the effects of winter weather, promoting the welfare of prepartum dairy cows.

Answer 444

 The discovery of common pulsotypes among milking equipment samples from different farms consistently sharing Staph. aureus with bulk tank milk samples shows the role of milking equipment as a source of Staph. aureus in on-farm bulk tank milk contamination

Answer 445

A long duration of UCD, severe lesions and higher parity reduced the chance of recovery. Among the recovered cows, 47% (59 of 126 cows) had a recurrent case of UCD after the recovery. In the treatment study, there was no difference in UCD score on d 56 between the treatment and control groups. Factors that affected the UCD score on d 56 were the duration of UCD before the treatment study started, UCD score on d 1 and udder conformation. Our findings emphasize the importance of further studies to identify effective treatment regimens as well as further studies to unravel the pathophysiology of UCD to improve the recommendations on how to prevent these lesions.

Answer 446

 Calves with Hp concentration ≤0.63 μmol/L at arrival were more likely to be diagnosed with BRD (and tended to have lower ADG) during the preweaning period  Hp was not associated with mortality  Circulating concentrations of l-lactate and cortisol measured at arrival were not associated with BRD incidence during the preweaning period

Answer 447

 A second treatment increased the risk of pregnancy in cows diagnosed with endometritis or PVD

Answer 448

 Capsular type was not associated with type of mastitis (subclinical, mild clinical, or moderate clinical).  Isolates containing the agrI gene and lacking the agr locus (agr−) were more prevalent among subclinical than clinical mastitis cases, whereas isolates containing the agrII and agrIII genes were more prevalent among clinical mastitis cases We found a strong association between agr type and type of mastitis, suggesting that knowledge of S. aureus genetic profiles could be an additional tool to control this disease.

Answer 449

 Cows inseminated from 7 to 24 h after onset of oestrus or from 1 to 18 h after peak of oestrus activity showed greatest pregnancy per AI irrespective of type of semen.

Answer 450

 Calves fed 15% BW in two feeds until week 5, then reduced by 50% until end of week 6. Starter, straw and water offered ad lib.  Starter intake increased from step-down until wk 12  Growth did not change during week 6, 7, 8.  Around weaning a prolonged ruminal pH depression was observed: dietary rumen adaptation after weaning can take several weeks in calves with a high MR feeding rate preweaning. The prolonged depressed ruminal pH did not affect acute-phase proteins and this finding, along with the other results, suggests that rumen epithelium barrier integrity is not compromised during weaning.

Answer 451

 Dry matter intake as a % of body weight changed quadratically with increasing hay, increasing from 0 to 5%, and decreasing from 5 to 10% hay.  Measures of digestibility increased up to 5% hay and declined thereafter  Addition of 5% chopped grass hay supported optimal digestion and growth in calves, but 10% hay decreased intake and digestion.

Answer 452

 the initial STP concentration of primiparous dairy heifers was associated with improved growth performance, especially greater body weight and withers height. In addition, with increasing levels of initial STP concentration, age at first oestrus, artificial insemination (AI) service, pregnancy, and calving was decreased by 16, 18, 25, and 25 d, respectively.  Initial STP concentration was positively correlated with milk production and increased total milk yield and yield of energy-corrected milk by about 1,558 kg and 1,149 kg during first lactation.  Calves with higher average starter feed intake during the last week of the preweaning period had better growth performance, which in turn was positively associated with fertility parameters  In the rearing period, particular attention should be paid to the initial STP concentration, average SI during the last week of this period, and rearing ADG to increase growth, fertility, and performance in the first lactation of primiparous dairy heifers.

Answer 453

 Cows fed for the long duration tended to have greater AUC for glucose but smaller AUC for insulin following an IVGTT than those fed for the short duration, thereby suggesting reduced insulin release and glucose disposal. Feeding acidogenic diets for longer period altered the responses to a glucose tolerance test and an insulin challenge with indications of reduced insulin release and sensitivity.  Cows fed acidogenic diets had increased abundance of lipolytic proteins and reduced abundance of lipogenic proteins in adipose tissue  Diet-induced metabolic acidosis altered insulin release and insulin signaling, resulting in a shift in adipose tissue metabolism that would favor lipolysis over lipogenesis.

Answer 454

 At 250 d, reducing the DCAD increased the AUC for glucose and reduced that of insulin following the IVGTT, whereas during the IC, clearance rate decreased and time to half-life of insulin increased with reducing DCAD, resulting in a tendency to a larger AUC for fatty acids.  At 270 d, quantitative insulin sensitivity check index and the revised quantitative insulin sensitivity check index were smaller in cows fed the acidogenic diets for the last 42 d of gestation compared with the last 21 d of gestation, thereby suggesting reduced insulin sensitivity. Diet-induced metabolic acidosis altered insulin release and insulin signaling, resulting in a shift in adipose tissue metabolism that would favor lipolysis over lipogenesis.

Answer 455

 Heat stress associated with a reduction in DMI of 20%  Heat stress decreased gestation length, first colostrum yield, and calf birth weight  Reduced feed intake during late gestation accounted for 60% of the total reduced milk yield during the first 50DIM

Answer 456

 High BTSCC associated with a reduction in milk yield  The lower the BTSCC, the greater the revenue, GM and NM, profit, and operational profitability of the herds.

Answer 457

 T1: 60d DP if given DCT, otherwise 30d or 0d DP based on MY >12kg/d. DCT cut off: parity 1 ≥50,000 cells/mL, parity 2+ >150,000 cells/mL.  T2: 60d DP if given DCT, otherwise 30d or 0d DP based on MY >12kg/d. DCT cut off ≥200,000 cells/mL  Compared with CT, cows in T1 and T2 on average produced more milk in the 8 wk before calving but less milk in the 14wks after calving  There was no difference in udder-health status in the transition period among decision trees  Overall, 30-d and 0-d dry periods reduced milk revenues, but this might be financially compensated by improved cow health with customized dry-period strategies.

Answer 458

 Pathogen-specific IMI traits and overall IMI had weak to moderate positive genetic correlations [ranging from 0.11 to 0.81 (±0.11 to 0.22)] with SCS. Therefore, selection for lower SCS will improve resistance to IMI.  Despite low heritability estimates, there was sizeable genetic variation for pathogen-specific IMI traits  Selection for lower SCC will not improve resistance to IMI from every pathogen-specific IMI group in the same manner, although in the long term pathogen specific reductions in IMI via genetic selection is possible

Answer 459

 Serum total protein and IgG for calves fed maternal colostrum were highly correlated.  In contrast, STP and IgG for calves fed CR were lowly correlated  A STP cutoff point that could predict FTPI when calves are fed CR would be 4.9 g/dL (sensitivity = 0.68; specificity = 0.75).  This study suggests that current cutoff points used for STP inflates the number of calves estimated to have FTPI when they are fed CR.

Answer 460

 meaningful differences were evident for visual lameness assessment and cortisol from meloxicam and flunixin treatment versus the positive control.

Answer 461

 MY losses are greatest during the first quarter after BVD introduction  BVDV introduction had a negative, but on average a relatively small, effect on milk yield of around 0.1kg/cow per day

Answer 462

 Cathelicidin and haptoglobin in subclinical mastitis quarters were significantly influenced by different bacteriological results  Milk amyloid A and Haptoglobin elevated in cases of clinical mastitis  The measurement of cathelicidin, milk amyloid A, and haptoglobin in milk proved to be a reliable method to detect quarters with subclinical or clinical mastitis

Answer 463

 Cows with SCC >200,000 cells/mL in the first month of lactation were considered to have SCM  Elevated SCC in the first month of lactation had detrimental effects on the milk yield and survivability of dairy cows in USDA organic herds, but it did not affect reproductive performance.  Cows with SCM diagnosed in the first month of lactation continued to have elevated SCC linear scores throughout their entire lactation, and that elevated SCC was carried over from the previous lactation.

Answer 464

 STP and source associated with testing positive for a pathogen at arrival  Calves with diarrhoea demonstrated a reduced rate of weight gain; up to 15kg by 77d  C. parvum and Bovine coronavirus associated with reduced BW gain.

Answer 465

 (1) position cubicles in a way that leaves more than 1 m of clearance from any obstacle in front of the cubicle;  (2) if there is an obstacle on the lateral plane (i.e., where the cubicle partition is) in front ahead of the cow, put the obstacle in front of the fore knees;  (3) if there is an obstacle in front of the cow on the median plane (e.g., neck or front rail), the position the obstacle between 1.25 and 1.5 of the cow length from the curb and between 1.0 and 1.25 of its height;  (4) use curb height between 0.11 and 0.15 of cow height with no sharp edges on the curb;  (5) use round or at least has no sharp edges brisket board;  (6) use a stone-free soil instead of concrete or use a mattress thicker than 1 cm, with microrelief, and a soft fixing area at the curb,  (7) litter with straw (rather than nothing or sawdust) and keep it dry. This risk factor analysis should be followed by experiments in controlled environments to further validate these conclusions and used to update the International Commission of Agricultural and Biosystems Engineering recommendations.

Answer 466

 The addition of dextrose for 1 or 3 d provided no improvement in resolution of ketosis assessed once weekly, reduction in adverse events during the first 60 d of lactation, or a difference in average daily milk yield during the first 10 wk of lactation.

Answer 467

 The number and severity of sole and white line lesions increased after calving.  Social environment did not influence standing behaviour, but did affect agonistic interactions and may have influenced the risk of claw horn lesions in the weeks following calving, although not significantly.

Answer 468

 Cows housed on farms with dirtier stalls had 1.3 times greater odds of being lame at the time of observation  No associations between cleanliness and SCC found in this study  Cows lie down longer in cleaner and more comfortable environments. Further, these results highlight the need for improved stall cleanliness to optimize lying time and potentially reduce lameness.

Answer 469

 In primiparous cows, serum Ca concentrations of cows with ketosis, acute puerperal metritis, and APM+ were significantly reduced on d 3 and 7 after calving, compared with healthy cows  A delayed onset of hypocalcemia (d 3 and 7) was indicative for the development of disease in primiparous cows  In multiparous cows, reduced serum Ca concentrations on d 1 and 3 were associated with occurrence of diseases.

Answer 470

In our study, the control measures recommended to the dairy farms appeared effective, such that 13 of 19 farms reached a low risk level during at least 3 consecutive negative samplings from calves, with no M. bovis mastitis detected subsequently. Among risk factors, insemination with an M. bovis-positive bull indicated a trend of increasing the odds of M. bovis infection on the farm in a multivariable logistic model. In contrast, higher herd average milk yield had an association with lower odds for M. bovis infection. Occurrence of other infectious diseases affecting several animals on the dairy farm in the previous 6 mo before M. bovis infection were more frequent on M. bovis-infected farms.

Answer 471

 Since the ban on BDCT, overall declines of 63% in AMUDCT and 15% in AMUIMM were observed.  the period since the ban on BDCT was associated with a Small but significant increase in the percentage of cows with high somatic cell count (HSCC) and new HSCC  SDCT can be introduced without substantial negative effects on udder health

Answer 472

 Application of a claw block significantly reduced lameness scores and differences in weightbearing across contralateral limbs in lame cattle at a walking pace, but it did not affect weight distribution when standing.  Additional methods of pain relief may be necessary

Answer 473

 Pregnant heifers either exposed to heat stress (average THI 77) or not during the last 60d of gestation  Cooled heifers had higher milk yield (35.8 vs. 31.9 ± 1.4 kg/d), when compared with HT heifers.  Similar to multiparous cows, our data indicate that actively cooling heifers in late pregnancy is effective in promoting thermoregulation and results in elevated milk production postcalving.

Answer 474

 Cows were classified as cyclic at 49 DIM if a CL was observed in at least 1 of the 2 examinations, or anovular if no CL was observed at either examination.  Anovular cows divided into three groups based on the diameter of the largest follicle: 8 to 13 mm, 14 to 17 mm, or ≥18 mm  The risk factors for the 3 distinct anovular follicle phenotypes differed.  Generally, anovular cows with smaller follicles had longer dry periods, less BCS at 35 DIM, and disease (mastitis, respiratory, reproductive, hyperketonaemia, GIT, lameness).  In contrast, cows with larger follicles (≥18 mm) were more similar to cyclic cows

Answer 475

- Body weight at first calving was not a strong indicator for first-lactation milk yield and long-term milk yield. o Whilst significant factors, they accounted for <3% of variation, suggesting they are not primary contributors to variation in MY - Heavier heifers lost more weight during the first month of lactation and subsequently faced higher risk of being culled than lighter heifers. - Optimal suggested maturity rate of 73-77% at first calving would allow milk production to be optimized during the first lactation without sacrificing long-term MY and herd life o Maturity rate = body weight at first calving as a percentage of mature body weight

Answer 476

- Although calving to first service interval was not related to services per conception, longer calving interval was related to increased services and decreased conception rate to first AI. (is this confounded?) - Effective lactation yield at most farms was greatest in cows with a calving interval from 364 to 531 d, especially for multiparous cows o For heifers on most farms, a CFSI of more than 196 d resulted in greatest o effective lactation yield, when high-yielding heifers (differs per farm; >7,500–11,000 kg of FPCM/305 d) were selected. o For cows on most farms, a CFSI of more than 140 d resulted in greatest effective lactation yield, when high-yielding cows (differs per farm; >9,500–12,000 kg of FPCM/305 d) were selected. Although at the majority of farms 305-d yield was greater in CInt ≥ 532 d, effective lactation yield at most farms was greatest in CInt from 364 to 531 d, especially for multiparous cows. Based on the results of this study, a CInt between 364 and 531 days seems most optimal for milk production, when high-yielding cows were selected.

Answer 477

- Milk yield did not differ among treatments. - Pregnancy at first AI did not differ, but pregnancy rate after the first AI was slower for calcitriol-treated cows because of reduced insemination rate and pregnancy per AI. - We found that CAL200 reduced death but increased culling in cows without calving problems. - Collectively, results indicate that treatment with calcitriol at parturition was effective in improving concentrations of iCa, tCa, and tP, which reduced the risk of hypocalcemia. - Pregnancy rate was reduced by calcitriol treatment, and benefits on health performance were limited to overconditioned cows. Thus, treatment of all cows is not supported, and proper identification of cohorts of cows that benefit from postpartum interventions that increase blood calcitriol or calcium is needed.

Answer 478

- Applying a higher milk flowrate switch point based as a percentage of the rolling average milk flowrate on the last milking quarter, did not produce a significant reduction in milking duration or time spent by individual cows in the AMS.

Answer 479

- Lactation length affected by: month of calving, parity (longer with increasing parity), breed (Norwegian red/montbeliarde shorter than HF cows) - Genetic factors could account for up to 9d of variability of lactation length - An approach which combines improved management practices and selective breeding may be an efficient and effective strategy to lengthen lactations.

Answer 480

- EED defined as: o blood BHB ≥ 1.2 mmol/L o milk BHB ≥ 0.14 mmol/L o mpbNEFA ≥ 0.55 mmol/L o de novo FA ≤ 22.7 rel % - Although the relationship between EED and CM is still unclear, our findings suggest that cows in EED, diagnosed using blood BHB or mpbNEFA during the first 18 DIM, have a tendency toward lower SCS compared with their non-EED counterparts.

Answer 481

- In severe UCD lesions, anaerobic bacteria Trueperella pyogenes and Bacteroides pyogenes were more frequently present in deep tissue layers and in superficial layers, compared with the same layers in mild UCD lesions or healthy skin. o Culturing and histopathology indicated no sign of involvement of treponemes, Staphylococcus aureus, Escherichia coli, fungi, or mites in the UCD lesions. - The majority of lesions were characterized by chronic aseptic inflammation

Answer 482

- Cumulative 60-d milk consumption, birth weight, feeder, days fed, year born, season born, respiratory incidence, scours incidence and genetic body size composite score were significantly associated with heifer BW at 400d o Heifers were 4.2 kg lighter at 400 d if treated for respiratory disease 3+ times during the first 60 d of life Measurements that can be obtained in the early life of dairy calves continue to influence heifer growth up to 400 d of age.

Answer 483

- Cows giving birth to larger calves (dam:calf BW ratio <14) had greater calving assistance, shorter rumination times during the first 30DIM and shorter resting times for the first week after calving. o The D:C ratio might serve as a useful index for the identification of cows at relatively higher risk of metabolic and inflammatory disease

Answer 484

- Somatic cell count, pathogen, parity, and THI had significant influence on pathogen shedding. - The pathogen shedding from mammary gland quarters with intramammary infections was higher in the first and second lactation than in higher lactations. - Exceeding the THI threshold 60 resulted in higher pathogen counts on the same day, but only for infections caused by yeasts and Streptococcus uberis

Answer 485

- We observed consistent diurnal patterns in both metabolites and a strong positive correlation between them. - Plasma NEFA reached a peak approximately 2 h before morning feed delivery, falling to a nadir in the late evening. - Plasma BHB was at a nadir at the time of morning feed delivery, peaking 4 h later. - The time relative to feeding should be considered when analyzing plasma metabolites, as classification of energy status may change throughout a day. - A single blood sample may not be representative of energy status of the early-lactation cow.

Answer 486

- Calf mortality rates were higher in herds whose calves did not have free access to water, and higher in herds hat had reported calf disease events - More than half of producers (59.6%) fed less milk than currently recommended for 3-wk-old calves (8 L/d first 3 to 4 wk)

Answer 487

- Cows preferred straw the most - When a Freestall was inserted with sand, cows would sacrifice surface for preference of greater free space - When lying down, dairy cows value an open lying space more than the lying surface

Answer 488

- Higher weight on arrival, creatine kinase, cholesterol, immunoglobulin G, iron, and copper were associated with improved calf health - Elevated zinc, haptoglobin, and molybdenum were negatively associated with calf health These results demonstrate that certain biomarkers could be used to identify high-risk calves when measured upon arrival at a veal facility. Future research should focus on determining the utility of these biomarkers to selectively target intervention strategies to improve ADG and reduce morbidity and mortality.

Answer 489

- The provision of a blind and lower stocking density may be beneficial for reducing inflammation before calving. - However, low prepartum stocking density might increase the odds of metritis after calving. - The reason for this paradox is unclear, the effects of prepartum stocking density may require further exploration.

Answer 490

- The prevalence of NAS was highest in the first 4 DIM. - The predominant species was Staphylococcus chromogenes accounting for 52% of IMI - S. chromogenes demonstrated the greatest persistency – 110d Vs 70d for other NAS species. - qSCC was highest in quarters having a pIMI with a major pathogen, followed by quarters having a pIMI with S. chromogenes, and a persistent IMI with other NAS. - No significant differences in qMY were observed between quarters having a pIMI or tIMI with S. chromogenes or with the other NAS species compared with noninfected quarters, despite the higher qSCC No significant differences in qMY were observed between quarters having a pIMI or tIMI with S. chromogenes or with the other NAS species compared with noninfected quarters, despite the higher qSCC. Quarters having a pIMI with major pathogens showed significantly lower daily milk production. Surprisingly, quarters that cured from an IMI with S. chromogenes had a significantly lower qMY than noninfected quarters.

Answer 491

- Serum retinol concentrations at close-up and early lactation were negatively associated with odds of developing postpartum hyperketonuria. - At early lactation, cows with uterine disease had lower serum retinol concentrations than cows without uterine disease. - First-test 305-d mature-equivalent milk yield was positively correlated with increased serum α-tocopherol and negatively correlated with β-carotene concentrations. This study demonstrates the potential for serum β-carotene, retinol, and α-tocopherol to serve as biomarkers for disease risk.

Answer 492

- Heifers trained on a phantom AMS machine prior to the onset of lactation showed a higher milking frequency and needed less fetching/training onto the machines

Answer 493

- Stall lameness scoring (SLS), allows observers to assess cattle for lameness while they remain in their stall. o Based on behavioural changes in weight bearing and foot positioning, which include: shifting weight, resting a foot, standing on the edge of the stall, and uneven weight bearing when stepping side to side. - Solar ulceration associated with a cow observed resting one limb and bearing weight unevenly - Solar haemorrhage associated with shifting their weight from one foot to another - Digital dermatitis associated with bearing weight unevenly

Answer 494

- A DD risk assessment questionnaire performed alongside prevalence determination, a report provided to farmers with suggestions for improvement, reevaluation of status 2yrs later - No relationship between risk score and DD prevalence was determinaed - Generally, vets did not follow up the results - Provision of a summary risk assessment was insufficient to initiate behavioural change that led to a decrease in DD prevalence We propose that the DD RAQ could be used as a tool to start a discussion on DD control on farm, but simply undertaking a DD RAQ and providing a 1-page summary of the results was insufficient to initiate behavioral change that led to a decrease in DD prevalence.

Answer 495

o BBP = sodium bicarbonate (50.7 mmol/L) o MBP = sodium bicarbonate (33.8 mmol/L), sodium citrate (8.4 mmol/L), sodium acetate (6.3 mmol/L), and potassium citrate (1.9 mmol/L) o HAL = sodium acetate (50.1 mmol/L) - Enrolled to tx when faecal score was 2 for 2d or 3; tube fed 1hr post milk replacer feeding - In cases of moderate dehydration, MBP improved the acid-base status of calves compared with BBP, whereas HAL performed similarly to MBP. o Increased blood CO2, bicarbonate, base excess, anion gap

Answer 496

- In-parlour HL M scoring during milking and a BTM sample taken and tested for anti-Treponema phagedenis-like antibodies with an antibody ELISA in 40 french dairy herds - The ELISA was able to discriminate herds with low (<10%) or high (>40%) DD prevalence.

Answer 497

- DNA-based assays did not detect any Treponema phagedenis from stable flies and house flies collected at a dairy experiencing an outbreak of digital dermatitis.

Answer 498

- there exists a lag relationship between daily milk yield and heat stress - Heat stress is associated with reductions in milk yield beginning and peaking 1d after maximum ambient temperatures and lasting for 3 days.

Answer 499

- A metabolic acidosis was detected 24hrs after treatment started in the negative DCAD group - Concentrations of iCa begin to increase 24 h after feeding the acidogenic diet, and it was greater in the DCAD group by 3d after supplementation - Tissue responsiveness to PTH and changes in blood concentrations of iCa and digestibility of Ca are elicited within 3 d of exposure to an acidogenic diet. - DCAD was associated with greater urinary loss of Ca, but improved apparent Ca digestibility, resulting in similar Ca retention

Answer 500

- At the doses we used, meloxicam (intramammary or systemic) did not lower inflammatory responses. - Meloxicam itself did not promote inflammation in the mammary gland. - During lipopolysaccharide-induced mastitis, meloxicam did not diminish the concentrations of markers for blood-milk barrier integrity, milk immune components, or the mRNA abundance of proinflammatory factors in mammary tissue. - Instead, intramammary meloxicam expedited the increase in somatic cell count during the challenge with a low dose of lipopolysaccharide

Answer 501

- Despite improved indicators of growth and development in the preweaning period in heifers offered more milk, there was very little indication that preweaning nutrition affected postweaning growth and performance. - Increasing the preweaning plane from 5 to 10 kg of whole milk/d increased circulating leptin concentrations and enhanced LH pulses at 15 wk of age, associated with an earlier onset of puberty. - Increasing the postweaning plane from 70 to 85% of concentrate dry total mixed ration resulted in greater leptin concentrations by wk 25, which was also associated with an earlier onset of puberty. I. The results indicated that increasing the pre- and postweaning planes of nutrition along with energy levels positively influenced several indicators associated with heifer development before 25 wk of age. Nevertheless, there was limited interaction in growth and development indicators between the 2 phases. II. Increasing the postweaning plane from 70 to 85% of concentrate resulted in greater circulating leptin concentrations, which may be linked to an earlier onset of puberty.

Answer 502

 There was no interaction between milk allowance and physical forms of starter on feed intake, average daily gain, feed efficiency, BW, and structural growth  Feeding high milk allowance to calves resulted in greater weight gain and preweaning body weight.

Answer 503

 Meloxicam did not affect apparent efficiency of absorption, serum total protein, or IgG uptake at 6, 18, and 24 h; however, meloxicam-treated calves had lesser IgG concentrations at 12 h  Meloxicam treatment did not affect MR intake, time of consumption of MR, total dry matter intake, or feed efficiency  Meloxicam-treated calves tended to consume more starter, had higher ketone levels suggestive of improved rumen development Results of this study suggest that meloxicam given at 0 h offers positive effects on starter intake, and possibly rumen development, of preweaned dairy calves. Treatment as pil, as compared with solved in CR, offered positive results for rumen development, indicated by lower blood glucose levels.

Answer 504

 Elevated DM intake decreases the effect of nitrate supplementation on CH4 production  Average DM, thus CH4 production was higher for dairy cows vs beef cows  Nitrate supplementation reduces CH4 production and yield in a dose-dependent manner  Increasing nitrate dose associated with decreasing CH4 production and yield.

Answer 505

 Some high-producing cows are better able to maintain high production when fed less protein (CP 13%).  Low dietary protein resilience was associated with greater protein efficiency when cows were fed low-protein diets and may be a desirable trait for comparing cows in the future.

Answer 506

AFC <22-23 months associated with reduced yields of milk, fat and protein. First calving later than 24 months associated with increased rearing costs, but the effect of older AFC on first lactation performance is less clear:  AFC was found to be the most important determinant of milk yield during first lactation  With an increase in ECM up to an age of 33 mo (R2 = 0.047)  Calving season (R2 = 0.01), Birth month (R2 = 0.002), Dam parity (R2 = 0.002) also associated with heifer first lactation MY.

Answer 507

 None of the models could predict cows that conceived to first insemination, with an accuracy around 0.48  MIR data did improve prediction accuracy when compared to the use of on farm data alone, with a prediction accuracy of 0.76 for identification of he bottom 10% of cows, which had the least likelihood of conception to first insemination.

Answer 508

 Lactose percentage (LP) tends to decrease in the presence of udder infection and with parity. Therefore, it can be hypothesized that cows exhibiting limited changes in LP across lactations have experienced fewer udder infections in their productive life and have a higher chance to stay longer in the herd than cows with more pronounced reduction of LP across lactations  Cows with a stronger reduction of LP across lactations (i.e., stronger and negative β, and greater and positive Δ) were characterized by lower milk persistency, impaired longevity, and worse udder health and morphology than cows with smaller reduction in LP across lactations

Answer 509

 Calves disbudded via each method on a different bud, in a different environment with red squares or blue triangles on the walls. Then placed in a neutral pen and time recorded in which pens they chose to lie down in.  48hr after disbudding calves spent more time in the pen associated with hot-iron disbudding compared with what would be expected by chance, but no difference between caustic and hot iron pens were found at 72 and 96hrs.  Calves initially remember caustic paste disbudding as a more negative experience than hot-iron disbudding, even with the use of sedation, local anesthesia, and analgesia.

Answer 510

 Supplemented calves exhibited greater concentrations of n-3 FA in plasma as free and phospholipid FA and some n-3 and n-6 FA-derived oxylipids in the first week of life in a linear fashion with increasing supplemental dose.  Supplementing colostrum linearly increased plasma concentrations of n-3 FA and metabolites and decreased biomarkers of oxidative stress, but did not alter oxidant status or affect health or growth.  60 mL of 1:1 ratio fish:flaxseed oil colostrum supplement did not enhance preweaning calf performance. Supplementing n-3 FA in a one-time meal may not provide the anti-inflammatory benefits observed with continuous feeding.

Answer 511

 Cows that received ASP produced 1.82 kg/d more milk (P = 0.048) compared with cows in the PLC group during the first 30 DIM  Cows that experienced DYS and received ASP (n = 13) produced 4.48 kg/d more milk compared with DYS cows that received PLC (n = 17)  Activity: There was no difference in lying times or activity between cows in the ASP and PLC groups  Pyrexia: There was no difference in the proportion of cows with pyrexia between treatment groups  There were no differences between ASP and PLC groups in BHB concentrations There were no differences in clinical disease events between treatments. Results from this study suggest that treating cows with ASP after calving may help improve milk yields and udder health, increase activity, and enhance fertility in dairy cattle under certified organic management.

Answer 512

 Dystocia associated with higher haptoglobin and substance P.  Heifers had higher concentrations of substance P and cortisol compared to multiparous cows.  Cows treated with aspirin tended to have lower concentration of haptoglobin and had lower concentration of substance P at 36 h compared with cows treated with a placebo.  Anti-inflammatory treatment after calving may decrease inflammation.

Answer 513

 Treatment based on early diagnosis with lung ultrasound and clinical scoring affected short-term lung health and growth and reduced mortality  Early antibiotic therapy limited progression of lung consolidation immediately following treatment, reduced the likelihood of requiring treatment within 7 d of BRD1, and improved growth and mortality before weaning.  However, lung disease eventually worsened despite multiple antibiotic treatments.  Despite receiving multiple doses of antibiotics after BRD1, calves treated with either antibiotic or placebo were equally likely to enter the weaning phase with pneumonia.  Clinical presentation was associated with response to treatment for worsening of consolidation, early treatment failure, days to retreatment, and average daily gain.

Answer 514

 Risk factors associated with a higher risk of a transition to any type of UCD and mild UCD were breed (Swedish Red vs. Swedish Holstein), an indentation or fold at the fore udder attachment, and increasing DIM.  A low milk urea level was associated with a lower risk of transition to any type of and mild UCD.  Cows with previous mild UCD and high-yielding cows had increased risk for a transition to severe UCD.  Cows that had an observed transition to severe UCD had an increased risk of veterinary-treated clinical mastitis within 6 wk after the UCD observation.  No associations were found between UCD and SCC or hock lesions.

Answer 515

 Total risk assessment questionaire, infectious RAQ and noninfectious RAQ score, had no association with the odds of a cow being lame or having an infectious or noninfectious lesion.  Herd size, milking frequency and routine foot trimming frequency were associated with infectious, noninfectious and noninfectious lesion presence respectively. Increasing parity was associated with a greater likelihood of lameness.  Lesions were reported in 93% of lame cows BUT only 21% of cows presenting a lesion were lame  Foot examination of only lame cows is likely to result in an underestimation of lameness prevalence Lameness prevalence in Alberta remains high, indicative of a low adoption rate of mitigation strategies by producers. Improvement of the RAQ could allow for better reflection of lameness and lesions on farm and can be achieved through further risk factor analysis within the RAQ, which may result in removal or addition of questions as well as the adjustment of scores based on risk factors' strength of association with lameness and lesions.

Answer 516

 No difference was detectable between treatment and control cows at 2 or 4 DIM with respect to blood ionized calcium concentrations  Continued acidification of dairy cows until 2 DIM did not result in clinically meaningful higher blood calcium concentrations compared with controls

Answer 517

 Cows with a negative outcome (median: 6.81 mmol/L) had significantly higher L-LAC than cows with a positive outcome (3.66 mmol/L) of therapy.  At the individual diagnosis level, L-LAC was associated with mortality in cows with a diagnosis of abomasal volvulus, local peritonitis, hemorrhagic bowel syndrome, and jejunal volvulus.  The largest area under the receiver operating characteristic curve for L-LAC was observed at 6 h (0.89). A cut-point of 1.77 mmol/L was identified, which had a sensitivity and specificity for predicting a negative outcome until hospital discharge of 88.9 and 73.4%, respectively  Persistent hyper-l-lactatemia during the early postoperative period is a more reliable indicator for a negative outcome than hyper-l-lactatemia before initiation of surgical intervention. The present analyses confirmed previous findings in calves and show that persistent hyper-l-lactatemia during the early postoperative period is a more reliable indicator for a negative outcome than hyper-l-lactatemia before initiation of surgical intervention.

Answer 518

 Regardless of parity, prepartum dams with a stillborn calf had reduced lying time (LT) and increased coefficient of variation of LT within the last 7 d before calving compared with dams with a calf born alive.  Multiparous cows with a stillborn calf had higher prepartum serum nonesterified fatty acid (NEFA) concentration compared with multiparous cows with a calf born alive, but this did not differ for first-calf heifers. These results show that the dam's prepartum LT and its consistency over time are associated with prepartum serum NEFA and calf survival at calving.

Answer 519

 Mycoplasma spp. were infrequently isolated from the vagina pre- (1.9%; 12/629) and post-bull (3.2%; 20/629) exposure  Cows whose conception during the bull breeding period was delayed, or who had not conceived, were more likely to have vaginal colonization with Mycoplasma bovigenitalium after bull exposure.  Cows that remain not pregnant for longer are more likely to be served by a bull (likely repeatedly) and subsequently become colonized with a Mycoplasma sp. (mostly M. bovigenitalium) through venereal transmission.  In dairy herds that use bulls, there is a greater chance of isolating a Mycoplasma sp. (mostly M. bovigenitalium) after a period of bull breedings from the vaginas of cows that have remained nonpregnant for longer during the bull breeding period.

Answer 520

 Skin tent return time, capillary refill time, and detectable enophthalmos were useful indicators of mild to moderate dehydration  Factors associate with a dehydration of 3.5-4.5% were: o Skin tent of >3 seconds (min 4.4% dehydration) o CRT of >3 seconds (min 4.3% dehydration) o Enophthalmos ≥1 mm – (min 3.5% dehydration)

Answer 521

 Calves all fed colostrum (7.5% BW, 62g IgG/L) at 2 hrs after birth, then assigned to be fed every 12hrs until 72hrs: o 5% BW colostrum o 5% BW whole milk o 5% BW colostrum:whole milk 1:1 mixture  Serum IgG concentrations were higher and more persistent in calves fed colostrum or a mixture, compared to those fed whole milk

Answer 522

 In infected herds, despite a high seroprevalence in the calves at weaning, only 4% were positive on culture from vaginal, conjunctival and nose swabs  M. bovis was isolated: o 0.5% at prebreeding o 0% prevalving o 0.3% 1 month postcalving  The nose was the predominant anatomical site of M. bovis colonization  A single heifer was repeatedly detected with M. bovis in its nose at weaning, prebreeding, and postcalving samplings. This demonstrates the possibility, albeit rare, of a long-term M. bovis carrier state in replacement heifers exposed to M. bovis as calves  For groups of 50 or more heifers exposed to M. bovis preweaning, there is at least a nontrivial probability that the group will contain at least 1 shedding heifer postcalving

Answer 523

 Short gestation length was a greater contributor to poor performance than dry period length itself  Short dry period length associated with higher somatic cell count and lower milk yield at first testing.  Long dry period length or gestation length did not influence milk yield  Long dry period length associated with more issues relating to fat mobilization: higher milk fat and milk fat:protein ratio, greater hazard of leaving the herd.  Deviations in DPL length caused by biology (short GL) were associated with greater effects than management causes of short DPL, whereas management reasons for long DPL were associated with more negative outcomes than long GL.

Answer 524

 Oral calcium (Ca) supplementation with 50 g of Ca as blend of calcium chloride, calcium sulfate, and calcium propionate increased intracellular polymorphonuclear leukocyte (PMNL) Ca in primiparous and multiparous animals.  Further, supplementing 50 g of oral Ca increased PMNL phagocytosis and oxidative burst among primiparous animals.  50 g of oral Ca for 2 d can increase intracellular PMNL Ca and restore some of the impaired PMNL function around parturition.

Answer 525

 Heifers conceived in summer had fewer follicles but similar fertility at first pregnancy compared with heifers conceived in winter.  Follicles were fewer in daughters of nonlactating versus lactating dams. Heifers with the lowest anti-Müllerian hormone (proxy of follicle numbers) had greater age at first service but not first conception compared with heifers with intermediate anti-Müllerian hormone. Season of conception and maternal lactation status affect the size of the ovarian reserve, but not fertility, at first conception in the progeny

Answer 526

 Fat depots contribute differently to lipomobilization and may vary in functionality  During the dry period significantly more adipose tissue is stored, and after parturition more is lost from abdominal compared with subcutaneous depots.  Before parturition, cows with high body condition gain about the same adipose tissue mass in abdominal and subcutaneous depots but mobilize significantly more mass from both depots after calving than do cows in low condition. The results indicate that feed efficiency may not be an adequate criterion for performance evaluation in cows during NEB. Greater knowledge of functional disparities between AAT and SCAT depots may improve our understanding of excessive lipomobilization and its consequences for metabolic health and performance of dairy cows during the transition period.

Answer 527

 Feeding a transition milk, or CR:MR blend was associated with greater bodyweight gains until weaning  No differences in health scores, but lower haptoglobin in TM and MR:CR fed calves

Answer 528

 Feeding a milk replacer containing a blend of bovine plasma protein and modified wheat protein (1:1) replacing about 44% of the whey proteins resulted in similar growth and greater starter intake than feeding an all-whey protein milk replacer.  Feeding the milk replacer in 2 feedings daily resulted in better growth and feed efficiency than feeding in 3 meals daily.

Answer 529

 Overall, the average daily gain (ADG), feed efficiency (ADG/dry matter intake) were similar across the treatments.  The implementation of step-down weaning in early life (4–6 wk of age) could stimulate solid feed intake compared with weaning at a later age with no negative effect on performance.

Answer 530

 Feeding a greater essential AA formulated milk replacer with specific concentrations resulted in calf growth performance, dry matter intake, and feed conversions that were similar to those of calves fed standard 22% CP, but the feed cost was lower for the AA milk replacer under current study conditions.

Answer 531

 new optimum range of milk urea between 150 and 250 mg/L was better suited to dietary crude protein intake in relation to demand  FPR >1.4 more Sn than 1.5  Energy oversupply or the risk of overconditioning could not be identified by milk constituents alone For these ketosis indicators, the new scheme had higher sensitivities. Energy oversupply or the risk of overconditioning could not be identified by milk constituents alone. Urinary acid-base content was not related to milk content. Similarly, milk testing data did not allow a clear distinction to be made between the diagnoses of acidosis and, for example, ketosis. Essential requirements for good herd management are the continuous observation of milk testing data in combination with other established instruments of feeding and animal monitoring.

Answer 532

 Milk FA <16 carbons originate soley from de novo lipogenesis  Long chain milk FA are produced by rumen microbes during biohydrogenation with resultant increases in milk trans-10 C18:1 (also known as conjugated linoleic acid)  Milk fat was linearly related to milk fatty acids <16 C, though the relationship was weaker compared with the relationship between milk fat percentage and specific de novo fatty acids and with previous publications.  These relationships provide tools to diagnose biohydrogenation-induced milk fat depression.

Answer 533

 Dry matter intake was increased in diets containing additives compared with the control. Feed efficiency was improved in monensin-supplemented heifers compared with sodium butyrate-supplemented heifers.  Compared with the control, additives decreased the number of coccidia in feces.  Overall, additive supplementation offers positive results in growth performance and improvement in overall health.

Answer 534

 Dry matter intake was increased in diets containing additives compared with the control. Feed efficiency was improved in monensin-supplemented heifers compared with sodium butyrate-supplemented heifers.  Compared with the control, additives decreased the number of coccidia in feces.  Overall, additive supplementation offers positive results in growth performance and improvement in overall health.

Answer 535

 In diarrheic calves, isotonic oral rehydration solutions prepared in water improve plasma volume and variables more rapidly than do hypertonic milk-based solutions.  Therefore, isotonic water-based oral rehydration solutions should be used for first aid therapy of calves with diarrhoea.  Thereafter, oral rehydration solutions prepared in milk combined with free water access can be used because they offer greater potential for increasing blood pH and osmolality than milk alone (milk has no alkalinizing ability and contains low sodium) and fulfill the energy needs of diarrheic calves.

Answer 536

 Cows that developed hoof lesions showed decreased daily lying duration in the early postpartum period (d20-120d) before being diagnosed with hoof lesions compared with cows that remained healthy.  We found no evidence for a difference in number of lying bouts, lying bout duration, and number of steps among cows that developed hoof lesions compared with cows that remained healthy

Answer 537

 Disbudded calves make greater use of environmental features that offer seclusion, with use of the shelter possibly reflecting an increased preference for social withdrawal or separation  Calves entered the shelter more frequently when empty, left more frequently when unoccupied, spent more time overall in the shelter  Disbudding even with recommended pain mitigation affects behaviour for at least several days.

Answer 538

 Blood Ca ≤1.4 mmol/L “clinically hypocalcaemic”, Subclinically blood Ca > 1.4 and < 2.0 mmol/L  The day before and the day of calving, the “clinically hypocalcaemic” group spent longer lying and had reduced activity compared to healthy or subclinically affected animals.

Answer 539

 Treatment of calves at high risk of developing BRB with either enrofloxacin or tulathromycin resulted in a consistently higher proportion of ciprofloxacin-resistant E. coli in fecal samples.

Answer 540

 Disease during early lactation (50DIM) significantly affected fertility and survival.  Reproductive disorders: Dystocia, twins, retained fetal membranes, metritis, and clinical endometritis  Other disorders: subclinical ketosis, mastitis, displaced abomasum, and pneumonia  As number of recorded diseases increased, resumption of ovarian cyclicity decreased  Both health events reduced chances of survival Survival was reduced by REP and OTH. The magnitude of these negative effects was variable, depending on season of calving and parity, but consistently increased with the number of health events during early lactation.

Answer 541

 Comparisons of cure rates demonstrated that CIA and non-CIA had comparable efficacy for treatment of nonsevere clinical mastitis in dairy cattle.  Additionally, for cows with nonsevere clinical mastitis caused by Escherichia coli and Klebsiella spp., bacteriological cure rates were comparable for treated versus untreated cows; therefore, there was no evidence to justify treatment of these cases with CIA.

Answer 542

 For older cows, calcium status at calving affected their postcalving behaviour  Cows with clinical disease were observed to have longer lying times per day and fewer steps in the 21 d postcalving  Low blood calcium is associated with significant long-lasting behavioural effects during the critical postcalving period.

Answer 543

 Calves are often fed cold milk from a large-aperture teat, but warm milk and sucking behaviour are believed to trigger the esophageal reflex  Radiographs showed no milk in the rumen, regardless of milk temperature and aperture size  The minimum milk temperature was estimated to be 8°C – associated with shivering

Answer 544

 Non-aureus staphylococci (NAS) was detected rectal feces from dairy cows in every sampled herd.  Staphylococcus arlettae, Staphylococcus auricularis, Staphylococcus chromogenes, Staphylococcus cohnii, Staphylococcus devriesei, Staphylococcus equorum, Staphylococcus haemolyticus, Staphylococcus hominis, and Staphylococcus vitulinus  Four, 16, and 12% of the healthy quarters, quarters with SCC >50,000cells/ml and clinical mastitis cases, respectively, were NAS positive.  NAS has the potential to cause a mild mastitis or increases in SCC

Answer 545

Klebsiella spp. counts in CBP-S were higher than in CBP-FB, and Streptococcus spp. and yeasts and fungi counts in CBP-S were lower than in CBP-FB. Total coliforms, Escherichia coli, and Staphylococcus aureus counts in CBP-S were higher than in CBP-FB in period 1, but did not differ between treatments in period 2. No differences were detected in lying time (15.5 h/d), and time needed to lie down was higher in CBP-FB (5.3 s) than in CBP-S (4.6 s).  The forest biomass–bedded pack was less appropriate than sawdust with regard to compost performance and cow comfort but better in terms of controlling microbial counts of some species.

Answer 546

 For both veterinarians and farmers, the perception of each cow-based measurement prevalence increased incrementally as the herd's true prevalence increased.  Overall, farmers and veterinarians underestimated cow-based measurements.  Farmers and veterinarians more accurately estimated lameness prevalence in herds with higher prevalence than in herds with low prevalence, suggesting a better awareness of the issue on farms with lameness problems.  Injuries were less accurately estimated in herds with higher injury prevalence compared with herds with lower prevalence, suggesting an opportunity for better knowledge transfer in this area.

Answer 547

0 = normal (firm but not hard); 25% DM 1 = soft (does not hold form, piles but spreads slightly); 22% DM 2 = runny (spreads readily); 16% DM 3 = watery (liquid consistency, splatters). 11% DM  Using observational fecal consistency scoring can accurately predict diarrhoea or a decline in fecal DM.

Answer 548

 Ovarian function during the second and third months postpartum was largely unaffected by uterine disease.  Uterine disease as defined in this study did not affect cyclicity, ovarian follicular growth, or plasma progesterone concentrations  The initial period of pregnancy establishment (d 18 to 22) appeared to be unaffected by uterine disease.  Diseased cows, however, had greater embryonic loss after d 22 (note: small sample size)  Pregnancy failure in cows with uterine disease arises from mechanisms that allow the pregnancy to be recognized and established but not maintained. In short, uterine disease as defined in this study did not affect cyclicity, ovarian follicular growth, or plasma progesterone concentrations. Percentages of healthy and diseased cows that were pregnant were similar from d 18 to 22 after artificial insemination. Greater embryonic loss was observed after d 22 in diseased compared with healthy cows, but this observation was based on a small number of pregnancies and should be studied further in larger trials with greater statistical power.

Answer 549

 NSAIDs did not prevent the mammary epithelial barrier opening by LPS; however, ketoprofen, flunixin meglumine, and meloxicam support the re-establishment of the barrier integrity.  Used in mastitis therapy at an optimized dosage the tested NSAID would likely support the recovery of milk composition. However, an overdose of NSAID would likely cause tissue irritation and in turn, a delayed recovery of the barrier permeability.

Answer 550

Genomic merit for daughter pregnancy rate was positively associated with insulin-like growth factor-1 and glucose concentrations, but GDPR was negatively associated with nonesterified fatty acid concentration. A positive association was observed between GDPR and hazard of estrus and number of estrus events within 62 d postpartum, duration of estrus, probability of activity peak, and probability of heat index. Conversely, GDPR was negatively associated with rumination nadir at estrus. We detected a positive association between GDPR and hazard of pregnancy. Selection for GDPR may improve the hormonal and metabolic status of cows postpartum, leading to earlier resumption of cyclicity, and may improve detection of estrus in commercial herds because it was positively associated with estrus characteristics.

Answer 551

 Clinical endometritis had the highest lactational incidence risk, whereas retained fetal membranes had the lowest risk.  The main risk factors for reproductive diseases were shortened close-up and dry periods, shortened and extended calculated gestation length, and concurrent nonreproductive health conditions.

Answer 552

 Summer-calving cows had approximately 5-fold higher concentrations of plasma tumor-necrotizing factor-α, whereas the degree of body weight loss had minor effects.  Chronic heat is more potent in dysregulating immune function by reducing white blood cells and increasing inflammation.

Answer 553

 By regulating energy and protein supply through roughage quality in a diet containing only 1 kg of concentrate/d it was possible to reduce the heifers' unproductive period from 26 to 22 mo of age without impairing lifetime milk production.

Answer 554

 Primiparous Holstein cows were submitted for first insemination after synchronization of ovulation, in which the interval from induction of ovulation to TAI was either 16 or 24 h. Cows in the group in which ovulation was induced 24 h before TAI had fewer pregnancies per artificial insemination than cows in which ovulation was induced 16 h before TAI.  Thus, earlier induction of ovulation relative to TAI with sexed semen decreased pregnancies per artificial insemination in primiparous Holstein cows.

Answer 555

 Feeding grass hay reduced weight gain, but all calves achieved a level of gain to meet growth goals for breeding and have minimal benefit from yeast supplementation  Calves are capable of accomplishing growth goals of >900 g/d when fed rations containing at least 20% alfalfa hay, 24.5% corn silage, or 11.3% grass hay

Answer 556

 The concentration of IgA and IgM in colostrum increased linearly with increasing Zn-Met supplementation  Similar observations were not found for the concentration of IgA and IgM in calf blood.  Supplementing prepartum cows with 40 mg of Zn-Met/kg of DM will potentially improve the passive transfer of immunity

Answer 557

 Feeding levels of grass hay >10% reduce growth and intake before 16 wk and alter ruminal fermentation patterns.

Answer 558

 Serum NEFA and BHB was greater for the high group postpartum than the other groups  The LO+HI feeding strategy provided no benefit over the LO diet.  The high-energy diet, even when fed for only 19 d in the 2-diet system, increased serum β-hydroxybutyrate and liver lipids.  Single-group, controlled-energy diets are a viable strategy, and heifers respond similarly to older cows.

Answer 559

 We developed a novel computer vision tool to detect digital dermatitis with moderate to fair ability to detect DD

Answer 560

 digital cushion thickness varied for Holstein and Jersey cows and bulls and also varied by stage of lactation, claw, and body condition score.  The genetic component of digital cushion thickness differed not only by foot and claw but also by breed.

Answer 561

 Milk leakage was observed in 24.5% of the cows between 20 and 52 h after dry off  Milking frequency had a significant effect on the odds of milk leakage o When the milking frequency was reduced from 3 times/d to 2 or maintained at twice a day, cows had 11 or 9times higher odds of leaking milk, respectively, compared with cows where the milking frequency was reduced from twice to once a day  Milk production 24 h before dry off was associated with milk leakage incidence o Cows with a milk production between 13 and 21 L or above 21 L had 2.3 and 3.1 times higher odds of leaking milk, respectively, compared with cows with a milk production below 13 L  From dry off until 30d after calving o Quarters with milk leakage were 2 times more likely to develop clinical mastitis o Cows with milk leakage had 1.5 times higher odds of intramammary infections (SCC or CM)

Answer 562

 Yield losses are associated with cows with severely impaired mobility o Loss of 1.4% for score 2, 4.7% score 3  Elevated somatic cell count is associated with all suboptimal mobility scores.  Extended calving intervals are associated with impaired and severely impaired mobility  Culling risk is higher for cows with all suboptimal mobility scores o Cows with a mobility score ≥1 were more likely to be culled during both scoring periods. Our study, therefore, shows an association between specific mobility scores and production and reproductive performance in spring-calving, pasture-based dairy cows scored during the summer grazing period.

Answer 563

 High claw vacuum up to 48 kPa increases milking performance because of higher milk flow and reduced machine-on time.  Negative effects of high vacuum on teat tissue are prevented by reducing vacuum during low milk flow (<2 kg/min) at the start and end of milking.  Using a high cluster detachment level (1kg/min) reduces machine-on time without a loss of harvested milk

Answer 564

 Factors associated with spontaneous metritis cure o Plasma haptoglobin (higher, less likely to cure, threshold 0.54mg/mL. AUC=0.64) o Days in milk at metritis diagnosis (More DIM, more likely to cure, 8d AUC = 0.67)  Performance was impaired when cows that developed metritis at ≤8 DIM or had Hp >0.54 mg/mL were left untreated.  Factors associated with metritis treatment failure (2x ceftiofur 3d apart): o Plasma haptoglobin (Hp >0.78 mg/mL) o Days in milk at metritis diagnosis (≤5 DIM) o Vulvovaginal laceration o Dystocia In conclusion, these data indicate that timing of the onset of metritis and inflammatory biomarkers could be used for the development of a selective therapy strategy for metritis, but more research is needed to identify more accurate predictors of metritis spontaneous cure and treatment failure.

Answer 565

 Rectal temperature was not significantly correlated with ear, SCAP, neck, or tympanic temperature for the daily and hourly studies.  Results suggest that temperature microchips measure temperature appropriately, but temperature is dependent upon the implant site in calves, and temperature measured at ear, SCAP, and neck implant sites cannot be used to estimate rectal temperature

Answer 566

 Mean plasma cortisol concentration were lower at all times in XYL compared with CON.  No significant difference was observed in substance P concentrations of Con Vs Xyl cows at any time.  No significant difference was observed between groups in time or in mass of feedstuff spent feeding or rumination time between groups or behavioural scoring.  Animals in XYL showed a significantly higher number of chews per bolus in the first 24 h after surgery (P = 0.02). In conclusion, administration of xylazine before LA results in lower stress levels for cattle during the course of LA, especially before being put into lateral and dorsal recumbency. Therefore, in the opinion of the authors, xylazine administration can be recommended before LA to improve the well-being of the animals during and after surgery.

Answer 567

 Total protein values ≥5.2 g/dL reduced the hazard of mortality  A rectal temperature >39.6°C was associated with an increased hazard of morbidity.  Calf dehydration was associated with lower ADG  Elevated lymphocyte counts (within the reference interval) at the time of arrival were associated with increased ADG and a decreased hazard of morbidity within the first 21 d at the facility  When measured 72 h postarrival, elevated lymphocyte counts were associated with a decreased hazard of morbidity, and a lymphocyte count in the middle of the reference interval (4.6–5.8 × 109 cells/L) was associated with a decreased hazard of mortality. This study demonstrates that machine DCC at the time of arrival and 72 h after arrival has potential for use in identifying high-risk calves that might require treatment, as part of selective antimicrobial therapy protocols, with the purpose of reducing antimicrobial use without sacrificing animal health in veal facilities.

Answer 568

 MY, components and lactation stage accounted for 5% of total population Ab response variation o natural log-transformed MAP antibody response was negatively associated with milk yield, positively associated with protein and fat production and varied throughout the lactation  At an overall population level, correction of the serological response for non-disease-associated factors has the potential to change the status of only a small number of cows

Answer 569

 Prediction accuracy of the network was 95% (with a sensitivity and specificity of 0.96 and 0.94, respectively), demonstrating the benefit of utilizing routine milk recording as a noninvasive method to alert farmers of cows potentially affected by bTB.

Answer 570

 Colostrum left raw or heat treated – 60mins at 60°C  Heat treatment associated with no reduction in IgG concentration but a reduction in IgA concentration of 8.5%.  Heat treatment associated with decreases in colostrum insulin and IGF-1 concentrations, 36% SCC and 93% total bacterial count  Several complement components and other proteins that decreased in abundance due to heat treatment.  Decreased abundances in calves fed heat-treated colostrum included several enzymes relating to carbohydrate metabolism, involved in glycolysis or glycogenolysis.

Answer 571

 Explanatory variables: o Bed length ratio = bed length (cm) on the farm/withers height (cm) of the observed cow o Lunge space ratio = lunge space length (cm) on the farm/withers height (cm) of the observed cow  The lying behaviour of large-framed cows was clearly modified given the cubicle dimensions in use on the study farms.  An increase in the bed length ratio was associated with: o Decreased proportions of lying down movements with (1) repeated head pendulum movements, (2) repeated stepping with front legs, and (3) hitting against cubicle elements o Decreased proportions of standing up movements with (1) shifting backward, (2) hesitant head lunge movements, and (3) hitting against cubicle elements; and an increased proportion of lying positions without physical contact with cubicle elements o A decreased proportion of cows with tarsal lesions  An increase in the lunge space ratio was associated with: o A decreased proportion of standing up movements with sideways directed head lunge movements To summarize, the lying behavior of large-framed cows was clearly modified given the cubicle dimensions in use on the study farms. In view of the consistency of the obtained results, we recommend adjusting the dimensions of cubicles so that they are suitable for cows whose body size meets the breeding goals of the farm.

Answer 572

 SCC classified using the first 2 milk recordings. Threshold of ≤75,000 cells/mL for “low”, >100,000 cells/ml for “high”  Only 51% of cows were low for both recordings  a higher proportion of Jersey heifers in the high category than swedish holstein or swedish red  Larger herd size, AMS systems, lower milk production associated with a greater proportion of low cows Overall, the results indicate a substantial need for prevention of subclinical mastitis in early-lactation PC as only 50% of these cows had low CSCC at both milk recordings after calving. Moreover, we conclude that CSCC categories may be a useful tool for identifying success and problem herds.

Answer 573

 The aim of the current study was to test whether motivation to walk affects gait attributes  Cows walked faster and had longer stride length and less variation in head bob when approaching the reward; these effects were similar in both sound and lame cows.

Answer 574

 Risk factors: o Dairy herds c.f. beef herds o Larger herds o Herds that participate in shows/markets o Herds that introduce cattle o Herds that share pasture, or with direct contact with other herds at pasture

Answer 575

 multiparous cows with a plasma IGF-I concentration less than 40 ng/mL 1 wk after calving were 3 times more likely to suffer from a uterine infection 4 to 5 weeks postcalving  Higher IGF-1 a week after calving associated with increased odds of responding to a CIDR protocol and risk of conception in heifers but not multiparous cows In conclusion, changes in circulating concentrations of plasma IGF-I early postpartum may help predict reproductive status of dairy cows.

Answer 576

 No effect of THI on fresh sperm variables was observed in either young or older bulls.  However, high THI at spermatogenesis negatively affected the cryotolerance of sperm cells.  Climate compromises not only sperm quality but also dairy bull fertility as measured by 56-d non return rate

Answer 577

 Cows that received forestripping in addition to wiping of teats had higher milk flow rates and less adverse teat tissue changes after machine milking. o Cows that were forestripped had lower milking unit on times and higher 2 minute milk yield, lower odds of teat tsue changes  Omitting the forestripping procedure in the milking routine might be inadequate to fulfill the cows’ physiological requirements for adequate milk letdown and result in extended milking duration.  This could potentiate adverse effects of machine milking on the teat condition, diminish animal well-being, and affect udder health

Answer 578

 Disease status was associated with greater serum concentrations of free fatty acids, beta-hydroxybutyrate, haptoglobin, rectal temperature, and lesser calcium on postpartum d 0, 3, 7, and 14. Prebreeding body condition score and body weight were greater in healthy cows. Odds of early ovulation were 1.92 times greater in healthy than diseased cows. We conclude that disease negatively affects early postpartum ovulation risk and is associated with measurable changes in periparturient physical activity and postpartum metabolic profiles.

Answer 579

 Diets contained 20% concentrate and 80% forage (dry matter basis), and were fed either as a control with a forage geometric mean particle size of 52 mm (CON; 11 cows) or as a diet with the forage particle size reduced to a geometric mean size of 7 mm (RED; 10 cows)  The concentration of total SCFA was not affected by treatment, but the proportion of propionate, a key glucogenic precursor in cattle, tended to be greater for RED  Reduction of forage particle size represents an effective approach to optimizing forage utilization in forage-rich diets

Answer 580

 Feeding 3-NOP from 3-105DIM did not affect dry matter intake (DMI), milk yield, milk component yield, or feed efficiency.  3-NOP associated with reduced methane production and increased hydrogen production  Also, the apparent total-tract digestibility of dry matter, organic matter, neutral detergent fiber, and gross energy was greater for the 3-NOP treatment

Answer 581

 Overall, the C700 calves recorded greater weaning weight, final BW, heart girth change, feed efficiency, and average daily gain (ADG).  Calves fed milk only more likely to have diarrhoea and pneumonia, as well as pyrexia  Feeding pasteurized colostrum to calves at 700 g/d potentially improved the growth performance and health status.

Answer 582

 2 milk feeding regimens (+ ad lib texturized starter blended with chopped hay and water)  Moderate: 0.66kg DM/day  High: 1.1kg DM/day  2 weaning strategies:  Abrupt: 7d step down  Gradual: 21d step down  Weaning body weight (BW), hip width (HW), and hip height (HH) were greater for HI compared with MOD calves.  Gradual weaning over 21 d proved effective when used to transition calves from a high (up to 1.1 kg) level of MR but was not different from a single-step 7-d weaning for calves weaned using a moderate (0.66 kg) MR regimen.  Calves fed a high-MR diet benefit from a gradual weaning process that ensures successful growth and development.

Answer 583

 Phantom cows are defined as cows that have been artificially inseminated <15 after mating start date, not subsequently detected in oestrus, and then diagnosed as nonpregnant on pregnancy examination at 49d after MSD.  Phantom cow intervention at 49d was generally profitable  The sensitivity of pregnancy diagnosis, the proportion of ineligible cows presented by the farmer for pregnancy diagnosis, and the prevalence of phantom cows were highly influential on the net economic return from phantom cow intervention

Answer 584

 Staphylococcal enterotoxin M may be associated with mastitis.

Answer 585

 24% of calves had FTP.  Risk of FTP not associated with age or sex

Answer 586

 There was a significant effect of heat load on the occurrence of CM in the contagious pathogen stratum, and less so for environmental strata.  Higher milk yield, middle and late stage of lactation, and older parity increased the risk of CM under heat load conditions.

Answer 587

 The loop-mediated isothermal amplification (LAMP) assay may allow rapid (<24hr) on site identification of mastitis causing bacteria in bovine milk  Compared with bacteriological culture with identification by mass spectrometry, these assays had an agreement of ≥0.80 on field samples, except for the Streptococcus spp. assay, which had moderate agreement.  The evaluated LAMP assays have the potential to enable fast and reliable on-site testing of clinical mastitis milk samples if the current elaborate method for sample preparation is replaced by a simplified protocol.

Answer 588

 Provision of brushes did not affect performance, but hay supported intake and growth during weaning.  Access to a brush reduced pen-directed sucking, particularly around the time of milk delivery, and both brush and hay access reduced nonnutritive sucking on a teat

Answer 589

 Multiparous cows treated with ASA produced 1.64 kg/d more milk compared with multiparous cows that remained untreated during the fist 60DIM  Cows treated with ASA had lower concentration of BHB and higher BCS at the start of lactation  Results suggest that an applied ASA treatment after calving may improve production and metabolic status of cows

Answer 590

 First-lactation cows were randomly allocated to 2 groups and challenged with Staph. aureus strain MOK023 (belonging to CC97) or MOK124 (belonging to CC151) MOK023 (CC97) Cows developed Subclinical mastitis Milder reduction in milk yield MOK124 (CC151) Cows developed Clinical mastitis Greater reduction in milk yield Higher SCC, IL-8, Anti-Staph¬ antibodies Higher milk neutrophil proportion  The outcome of mastitis mediated by Staph. aureus is strain or genotype dependent.

Answer 591

 Low forage diets were associated with less time eating and ruminating  Primiparous cows demonstrated greater chewing and ruminating activity per kilogram of DMI, as well as adapted sorting behaviour in favour of large particles during the low-forage high-starch feeding  Nonetheless, Primiparous cows were more susceptible to SARA and increased liver enzymes  This suggests higher forage fiber requirements for PP cows and the need for improved feeding strategies to mitigate rumen fermentation disorders during early lactation in these cows

Answer 592

 Calves experience ongoing pain 11 d after hot-iron disbudding, adding to a growing body of evidence that pain persists for weeks after the procedure.

Answer 593

 Using multiplex PCR and PCR-restriction enzyme analysis (PCR-REA) methods, is was possible to identify C (cattle) and S (sheep)-types of mycobacteria.  Information on the types of MAP found in herds with low seroprevalence can help to determine the source of mycobacteria, which is important if animals from different regions or countries are present in the herd.  Because of difficulties in culturing S-type MAP for identification tests, we suggest the use of DNA derived from direct isolation of genetic material by PCR-based methods

Answer 594

 Protein yield and cheese production were affected by heat stress with average THI threshold of 74.  The THI thresholds identified indicate that the Brown Swiss breed has higher thermal tolerance versus literature values reported for Holstein cows.  As THI rises, Brown Swiss cows tend to produce the same volume of milk, but with a decreasing quality with regard to components.

Answer 595

 Cows exposed to heat stress have extended involution with delayed apoptosis and autophagy signaling. Also, heat stress compromises mammary gland cell proliferation and leads to higher connective tissue later in the dry period.  Heat stress impairs overall mammary gland turnover during the dry period, which then affects secretory activity and productivity in the next lactation.

Answer 596

 Skin temperature is appropriate to estimate chronic heat stress and that THI is the best environmental indicator of heat stress in dairy calves raised in a shaded, subtropical environment.  At a practical level, calves should be closely monitored when THI reaches 65 to 69 to minimize the risk of heat stress–related impairments.

Answer 597

 SCB calves had higher secretory IgA concentrations in the ileum and colon  Endogenous IgA production in the gut of SCB calves was enhanced, which could make them less prone to pathogen intrusion

Answer 598

 Extended colostrum feeding during 72 h after birth upregulated the expression of α-adrenergic and serotonin receptor genes and increased the abundance of Lactobacillus spp. and Escherichia coli in the gut.  Colostrum feeding strategies may affect the interaction between gut microbiota and neuroendocrine functions in calves.

Answer 599

 No changes in stress markers such as cortisol and haptoglobin in serum were detected. In conclusion, supplementing 4.5 g/d of Trp via MR between 48 and 62 d of life had no effect on performance or behaviour in calves around weaning.

Answer 600

 Increasing glucose inclusion (at the direct expense of lactose) in MR did not affect growth but linearly increased mortality, primarily associated with GIT disorders.  High glucose inclusion levels in MR affected calf mortality and is not a suitable strategy for lactose replacement.

Answer 601

 Negative DCAD +/- Ca supplementation associated with improved postcalving DMI, less subclinical hypocalcaemia, no differences in milk production, less adverse health events and lower somatic cell counts.  Acidogenic diets improved postcalving blood calcium and health outcomes and tended to increase dry matter intake postcalving. Additional calcium in the acidogenic diet had little effect.

Answer 602

 Frequency of diet delivery to cows had no effect on nutrient intakes, digestion, or milk production  Delivering the diet once daily caused a decrease in enteric methane energy losses (relative to gross energy intake) compared with delivering the diet twice or 4 times without affecting intake and milk production.

Answer 603

 A strain of Streptococcus uberis (SR115), 2 strains of Staphylococcus aureus (SA3971/59 and SA1), and a strain of Escherichia coli (P17.14291) were tested in vitro for their ability to grow in the presence or absence of bismuth subnitrate  A reduction of growth in the presence of bismuth subnitrate occurred for all the strains tested; although the extent varied by strain and species

Answer 604

 ABS alone to all quarters  ABS + ITS to all quarters  ABS to infected quarters and ITS to healthy quarters  ABS and ITS to infected quarters and ITS to healthy quarters  There was no significant difference between the 4 treatment groups regarding acquisition of new IMI or persistence of pre-existing IMI  There was no difference regarding incidence of clinical mastitis, mean somatic cell score, MY during the first 120 DIM  Quarter-based selective dry cow therapy was not inferior to BDCT, but resulted in a 48.3% probability of avoiding antimicrobial treatment

Answer 605

 When switched to a diet that did not meet energy demands for production, cows altered their feed sorting behaviour by increasing their sorting in favor of the smaller, more energy-dense components of the diet and against the longer, less energy-dense portions of the diet  Greater NEFA concentration was associated with greater sorting in favor of short particles (4-8mm) and against long particles (>19mm).

Answer 606

 The ADDDTOTAL and ADDDDCT were comparable between AMS and CMS farms,  ADDDIMM tended to be lower and ADDDINJ higher on AMS farms than on CMS farms.  The distribution of mastitis-causing pathogens and their antimicrobial resistance were comparable between AMS and CMS farms.  Similar AMU between Dutch conventional and AMS farms  AMS associated with more injectable use, and less IMM use

Answer 607

 Cows with fever spent less time feeding.

Answer 608

 The combination of a local anesthetic with a nonsteroidal anti-inflammatory drug is the most beneficial for reducing indicators of pain and inflammation in young calves disbudded with caustic paste.

Answer 609

 Vaccine 3 = recombinant subunit proteins  Vaccination significantly reduced the incidence of puerperal metritis  Reproduction was improved for metritic cows that were vaccinated  Positive effects were stronger for cows that were treated with vaccine 3  In general, vaccination decreased the total vaginal bacterial load and decreased the vaginal load of F. necrophorum by 9 d in milk

Answer 610

 Chitosan did not improve the cure of metritis, and was detrimental to milk yield, survival, and fertility compared with untreated controls  Treatment with ceftiofur increased cure of metritis, milk yield, and fertility compared with untreated cows.  Clinical cure was achieved in 12d in 2/3 of untreated cows, vs 70% of antibiotic treated cows

Answer 611

 Increasing levels of milk somatic cell count were negatively associated with the mammary synthesis of fatty acids

Answer 612

 Purchase practices, shared manure truck, shared materials, and visitors per month who contacted animals were found to be significantly associated with farm MAP infection status.  Purchase practices and herd size (included as a potential confounder) are the variables that best predict MAP status.

Answer 613

 Dry matter intake pre- and postpartum were unaffected by treatment, as was milk yield and milk component yields  Treatment increased circulating insulin concentrations, reduced NEFA and BHB concentrations as well as haptoglobin.

Answer 614

 In contrast to oral Ca supplementation, we have demonstrated potential negative consequences (i.e., decreased milk yield and slower return to baseline DMI) of intravenous Ca infusion during immunoactivation and demonstrated little to no benefit of maintaining eucalcemia on leukocyte function

Answer 615

To compare the serum immunoglobulin G (IgG) concentrations of dairy calves from birth until wk 16 of life when fed either maternal colostrum or colostrum replacer  4 treatment groups:  CR: 110g or 150g IgG total  Low quality MC supplemented with CR: 41g IgG/L, 154g total  High quality MC: 106g IgG/L, 401g total  Calves fed CR had serum IgG below 10gm/ml for a greater proportion of their first month of life  Lowest IgG levels occurred between 21d and 46d (earlier in calves fed CR than MC) Overall, the interaction between type of colostrum fed and sampling time was significant. Individual differences for this effect were found at d 1, 7, 14, 21, 28, and 98, while the other time points were not different.

Answer 616

 Milk production of daughters of heat stressed mums during gestation was reduced in first second and third lactations, was associated with earlier culling and reduced lifespan  Granddaughters of heat stressed mums during gestation produced less milk in their first lactation and more were culled prior to first lactation.  Late-gestation heat stress exerts carryover effects on at least 2 generations.  Providing heat abatement to dry-pregnant dams is important to rescue milk loss of the dam and to prevent losses in their progeny.

Answer 617

 The proposed standard includes 4 serum IgG categories: excellent, good, fair, and poor with serum IgG levels of ≥25.0, 18.0–24.9, 10.0–17.9, and <10 g/L, respectively.  At the herd level, we propose an achievable standard of >40, 30, 20, and <10% of calves in the excellent, good, fair, and poor categories, respectively  Because serum IgG concentrations are not practical for on-farm implementation, we provide corresponding serum total protein and %Brix values for use on farm:

Answer 618

 During the milk feeding period, methane emission and intensity, expressed as methane per body weight, were lower in animals fed a high level of milk replacer.  Emissions were comparable post weaning

Answer 619

 Furthermore, rumen-protected choline increased milk yield only when it was fed without supplemental methionine to multiparous cows, whereas rumen-protected choline increased milk yield for primiparous cows irrespective of methionine supplementation.  These results suggest that choline and methionine requirements during the periparturient period differ between primiparous and multiparous cows.

Answer 620

 Supplementation with 104mg ZnO reduced the incidence of diarrhoea during the first 3 d and increased serum immunoglobulin G and immunoglobulin M concentrations.  Supplementation with 457mg Zn-Met promoted growth and reduced diarrhoea for 14 d after birth  In view of their differing effects, we recommend ZnO supplementation for dairy calves during their first 3 d of life and Zn-Met supplementation for the subsequent period.  Zinc supplementation may be an alternative to antibacterial agents for the treatment of newborn calf diarrhoea.

Answer 621

 Inclusion of 3-nitrooxypropanol (3-NOP), administered via the total mixed ration at targeted concentrations of 0 to 200 mg/kg of feed dry matter, quadratically decreased daily enteric methane emissions.  3-NOP had no effect on dry matter intake or milk yield but linearly increased milk fat concentration and yield.

Answer 622

 Supplementing vitamin E did not affect milk somatic cell counts or colostrum quality but improved reproductive performance (reduced calving-first ooestrus period, days open, services per conception, retained placenta) of the cows, most likely because of enriched levels of serum vitamin E. For some variables, the positive effect was amplified by concomitant selenium supplementation.

Answer 623

 TMR provision associated with development of increased fibre digestibility at the cost of reduced weight and structural growth – as a consequence of increased hay consumption but reduced starter and total DMI.  If managed, the subsequent increase in fiber digestibility allowed for calves to be converted to a 15% grass hay TMR as early as 8 wk and still achieve desirable growth goals.

Answer 624

 In this study with only clinically healthy cows, no differences in postpartum serum calcium concentrations or neutrophil function (phagocytosis and oxidative burst activities) were found between treatment and control groups.

Answer 625

 The fibril modulus (Ef) and permeability (k) respectively increased and decreased in ulcerated claws compared with healthy claws only for zone 6  Ulcerated claws had a higher prevalence of exostoses compared with healthy ones  Histology scores equal to or greater than 3 were associated with macroscopic presence of ulceration. Sole soft tissues showed, as hypothesized, a viscoelastic behavior using unconfined compression testing, which, however, may not reflect in vivo loading conditions. Clinical and histological signs of sole ulceration were not associated with decreased strength of the supportive apparatus of the distal phalanx in zone 4 in this study.

Answer 626

 Blood plasma NEFA levels (>0.6 mmol/L), could be identified with a sensitivity and specificity of, respectively, 0.831 and 0.800.  Morning blood plasma NEFA levels were predicted with significantly higher accuracy using MIR spectra of evening milk samples compared with MIR spectra of morning samples – suggesting a time delay between blood plasma NEFA and milk biomarkers

Answer 627

 Purchasing or introducing cattle, rearing replacement heifers offsite, showing cattle at competitions, sharing transport vehicles with other herds, and transporting cattle in vehicles that have not been cleaned and disinfected were considered in the model.  Farms that purchased cattle from within their region (i.e., local movements) and shared transport with other farms had a higher probability for BVDV and BoHV-1 introduction.

Answer 628

 Culture- and algorithm-guided SDCT each reduced antibiotic use at dry-off by 55% without causing any negative effects on intramammary infection dynamics during the dry period  Culture- and algorithm-guided SDCT had no negative effects on clinical mastitis, risk of removal from the herd, somatic cell count, or milk yield during the first 120 d of the following lactation. These findings indicate that under the conditions of this trial, culture- and algorithm-guided SDCT can substantially reduce antibiotic use at dry-off without negatively affecting IMI dynamics.

Answer 629

 Lambs inoculated with colostrum spiked with BLV-infected cells or cell-free BLV showed evidence of infection 60 d after inoculation, whereas none of the lambs inoculated with spray-dried colostrum showed evidence of infection 60 d after inoculation  The risk for BLV transmission could be reduced if milk and colostrum were treated by spray-drying prior to consumption in dairy facilities.

Answer 630

 More than one-fifth of dairy cows have endometritis diagnosed either by PMN% or PVD in seasonal breeding herds when assessed at an average of 41 DIM,  There is large and unexplained variation in prevalence of endometritis among herds.  The 2 diagnostic methods were both associated with reproductive outcomes but have low levels of agreement between them and their effects appear to be independent.

Answer 631

 Cows grouped by the presence of parallel, straight, and cow-hocked hind limb conformation.  The principal characteristic of all 3 conformation traits was a significantly higher load on the lateral claws compared with the medial claws  After functional foot trimming, the claws of the cows with straight conformation tended to have the most pronounced disproportion between the loads of the paired claws.  These findings may help explain why genetic selection for claw health based on hind limb conformation has a low efficiency.

Answer 632

 Continuous gradual weaning: milk allocation reduced in small, equal increments from 12.5 L/d on d 43 to 2 L/d on d 56.  Multi-step gradual weaning: offered 10 L/d on d 43 to 45, 8 L/d on d 46 to 49, 6 L/d on d 50 to 52, and 3 L/d on d 53 to 56.  Both gradual weaning programs resulted in similar performance and intakes.  Calves with their solid feed located adjacent to their source of milk had improved nutrient consumption and growth compared with calves that had their solid feed located opposite the source of milk.  10% greater ADG during the preweaning phase  Placement of solid feed next to the milk source was demonstrated to increase feed, water, and milk intake during the preweaning stage, contributing to greater growth.

Answer 633

 Post-milking decreases in teat blood circulation is due to vacuum-induced forces during machine milking

Answer 634

 On-farm milk progesterone profiling using a lateral flow immunochromatographic test was able to identify cows without functional corpus luteum and to predict fertility outcomes following timed AI.  Cows with nonoptimal milk progesterone profiles had fewer pregnancies per AI and could be targeted for alternative synchronization programs tailored to their physiological status to improve reproductive performance.

Answer 635

 Primiparous cows, immunized with a J-5 Escherichia coli vaccine during late pregnancy, were challenged with E. coli during the periparturient period  Primiparous cows responded mild to moderately to intramammary E. coli challenge with little clinical difference between treatment groups  Even in the nonvaccinated animals, the E. coli challenge in the primiparous cows elicited only a mild to moderate response.  There was no clinical difference between vaccinated and unvaccinated animals.

Answer 636

 Molasses-based liquid feed supplementation (1kg/cow daily) in a dry cow diet resulted in greater DMI, less sorting, more frequent meals, and increased feeding rate during the dry period.  Post-calving rumen health was improved for cows previously fed a dry diet with molasses-based liquid feed supplementation.

Answer 637

 Monocytes and macrophages represent the main type of milk leukocyte from healthy mammary glands.  Quarters with nonspecific mastitis showed the highest percentage of milk CD4+ T lymphocytes  An increase in CD4+ T lymphocytes is correlated with low bacterial shedding  Milk leukocyte populations markedly fluctuate under healthy and inflammatory conditions.

Answer 638

 blanket administration of a cloxacillin dry cow therapy product  Final models indicated that measures of quarter-level IMI dynamics were similar between ITS groups  Lockout was found to be equivalent to Orbeseal for dry period new IMI risk  No differences for clinical mastitis and culling or death  No differences in SCC and milk yield

Answer 639

 RID = gold standard for measurement of passive transfer  Compared centrifuged serum, centrifuged plasma, filtered plasma and ELISA, capillary electrophoresis (CE), Brix refractometer, and handheld optical refractometer.  All methods highly correlated with RID:  CE = r = 0.97  ELISA = r = 0.90  Brix = r = 0.84, 0.8 and 0.78 for centrifuged serum, centrifuged plasma, or filtered plasma  Optical refractometer = r = 0.83, 0.81, and 0.80 (as above, respectively)  All 4 analytical methods used in the present study were suitable for assessing FPT in neonatal calves, regardless of the medium used.  Different cutoffs should be used if different media are used: Serum, Centrifuged plasma and Filtered plasma Optical refractometer 5.0g/dL 5.5g/dL 5.5g/dL, resp. Brix 7.8% 8.6% 8.8%, resp Optimal thresholds for assessing FPT using plasma were higher than for serum, regardless of the method of plasma harvesting. The 4 different devices had comparable areas under the curve, irrespective of the medium used. All analytical methods can be used to assess FPT.

Answer 640

 Lame = score ≥3/5, treatment SID for 2d with 2.2mg/kg flunixin IV + 5 step trim.  Drug treatment had no meaningful effects on post-trimming outcomes.  However, nonlame cows spent more time lying down after trimming, whereas lame cows did not.  Trimming in nonlame cows should be scheduled for a time when subsequent lying times can be accommodated

Answer 641

 Automatic cluster flushing with cold water was effective in removing S. aureus from teat cup liners  Addition of peracetic acid is therefore not necessary  Correctly functioning automatic flushing with cold water is thus expected to prevent udder infections on farms where teat cup liner contamination contributes to transmission between cows.

Answer 642

 Mats were ineffective  The most effective and efficient method was co-location of the spray water and fan at the feed bunk.

Answer 643

 Calving location differed by parity  Cows and heifers with access to pasture changed their lying and exploratory behaviour on the day of calving compared with a previous day.  On the calving day, cows spent more time lying down with more short bouts of lying, and crossed more sections. Steps were affected by an interactive effect of day, parity, and heat stress; nulliparous heifers took more steps on the calving day during conditions of heat stress compared with no heat stress.  39% calved in the barn, 26% calved in the open pasture, and 35% calved in the area with natural forage cover.

Answer 644

 Calving location differed by parity  Cows and heifers with access to pasture changed their lying and exploratory behaviour on the day of calving compared with a previous day.  On the calving day, cows spent more time lying down with more short bouts of lying, and crossed more sections  39% calved in the barn, 26% calved in the open pasture, and 35% calved in the area with natural forage cover.

Answer 645

 We found a very strong correlation between mean respiration rate (MRR) and mean rectal temperature  RR of 48 associated with the onset of heat stress at a rectal temp of 38.6°C  A time interaction was observed: MRR was greatest at 0630 until 0800am

Answer 646

 Calves fed only either 2x2.5L milk with OES or 2x3L water with OES.  Providing sugar and electrolyte mix in water and in milk replacer to calves without access to water resulted in hypernatremia (serum Na+ >145 mmol/L) and delayed recovery from diarrhoea.

Answer 647

 Samples analyzed for ionized calcium, ionized magnesium, chloride, glucose, and lactate were stable up to 8 h of storage  However, sodium and potassium did not prove to be stable.

Answer 648

 A decrease in plasma progesterone concentration was the most accurate test for predicting calving within 24 h – reductions begin at 35hr before calving – but due to equipment requirements for measurement it is likely impractical  Plasma glucose was an accurate predictor of parturition within 6hrs – increases occur as a consequence of maternal HPA axis activation, hypercortisolaemia and hyperglycaemia.

Answer 649

 Higher plasma glucose at the time of LPS inoculation associated with speeder recovery of DMI and MY  The metabolic status of cows in terms of circulating glucose and ketone bodies is clearly associated with responses during the lipopolysaccharide challenge as well as the recovery of udder health and performance thereafter.

Answer 650

 Heat stress group – environmental temperature of 36°C  Heat stress did not have significant effects on luteolytic responses or circulating progesterone concentrations. Rapid and complete luteolysis occurred in all cows given 25 mg of PGF2α

Answer 651

 Supplementation of 12.9g/d choline ion during transition increased fat percent and yield, energy corrected milk yield until 105d postpartum  Supplementation did not affect postpartum DMI, but increased feed efficiency  No additional benefit was observed from supplementing RPC past 22 d postpartum. Collectively, supplementing RPC to supply 12.9 g/d of choline ion benefited productive performance in dairy cows when supplementation occurred during the transition period, but no additional benefit was observed from supplementing RPC past 22 d postpartum.

Answer 652

 Supplementation with 12.9 g/d of choline ion in RPC form from 21 d prepartum to 21 d postpartum improved productive performance of dairy cows, whereas supplementation with the same amount of RPC from 22 to 105 d postpartum did not further affect lactation performance  Choline supplementation reduced the incidence of subclinical hypocalcaemia  Choline supplementation increased plasma triacylglycerol – a consequence of increased production without concomitant increases in DMI Supplementing transition cows with RPC did not affect the concentrations of liposoluble vitamins in the first 7 d postpartum or the incidence of individual diseases or morbidity in early lactation. The inability of supplemental choline to reduce hepatic triacylglycerol might have been a consequence of the increased productive performance without additional dry matter intake.

Answer 653

 Neonatal Holstein bulls were fed colostrum at 2 h after birth and then colostrum, a colostrum-milk mixture, or milk every 12 h from 12 to 72 h.  Extended colostrum and colostrum-milk mixture feeding heightened small intestinal villi and increased absorptive surface area. Overall, extended COL feeding minimally increased plasma GLP-2 and serum IGF-1 compared with WM feeding.  These results suggest that producers may feed colostrum or transition milk past 24 h postnatal to benefit neonatal intestinal development.

Answer 654

 Increasing fat content at the expense of lactose decreased CMR intake by 10%, whereas total calculated metabolizable energy intake and growth remained equal between treatments.  There was a significant decrease in the total number of health events (mainly respiratory) requiring therapeutic intervention and in the total number of therapeutic interventions in calves fed high-fat CMR.  Increasing fat content in CMR resulted in a decreased ad libitum CMR intake with equivalent body weight gain and solid feed intake.  High-fat CMR was associated with a lower number of health problems.

Answer 655

 Increasing forage proportion increased ruminal pH and milk fat concentration and improved milk efficiency, but milk yield decreased due to decreased feed intake.  The benefits of increasing physically effective fiber content of diets by increasing forage proportion may be partially offset by decreased intake and losses in milk yield.  In contrast, increasing dietary forage particle length increased ruminal pH without negative effects on feed intake, rumen fermentation, nutrient digestibility, and milk production.  The paNDF model showed improvement in the predictability of ruminal pH over the peNDF model.  Increasing the ratio of forage to concentrate from 35:65 to 60:40 decreased the intake and flow of amino acids to the duodenum, but effects of forage particle length were minimal. Increasing the forage concentration of the diet caused a deficit in amino acid supply to the small intestine, indicating that supplemental rumen undegraded protein may be required in high-forage diets to meet the amino acid requirements of lactating dairy cows.

Answer 656

 Involved feeding 40 calves texturised calf starter and chopped hay as separate components or as a mixture of 90% calf starter and 10% hay.  The study results suggest that calves had greater intake and average daily gain when they were fed hay and calf starter separately compared with receiving the same feeds as a mixture.

Answer 657

 Heifers that were heavier at 6, 12, and 15 mo of age were more likely to remain in the herd for first, second, and third calving compared with heifers that were lighter. Additionally, heavier heifers were more likely to calve early for first calving compared with heifers that were lighter.  For heifers that were below average in BW, considerable benefits for stayability and reproductive performance could be achieved by improving rearing practices to result in heavier heifers throughout the pre-breeding rearing phase.

Answer 658

 We found that rumen microbial composition explains a larger proportion of the variation in milk concentrations of acetone and BHB than do host genetics. Moreover, we identified associations between milk acetone and BHB with some specific bacterial and archaeal operational taxonomic units previously reported to have low to moderate heritability, presenting an opportunity for genetic improvement.

Answer 659

 Scrubbing the teat end with alcohol after pre-milking disinfection with an iodine-based teat disinfectant and drying of the teat with a single use towel minimizes contamination of the milk sample.  Environmental species were more likely to be identified among contaminated samples, whereas host-adapted species were more likely to be identified among uncontaminated samples.

Answer 660

 Both Holstein and Jersey multiparous cows had longer lying times than cows in first parity after parturition  The lying time of multiparous cows decreased, whereas that of primiparous cows increased in the beginning of lactation  Breed and parity have strong effects on eating and lying behaviour, with lying behaviour changing throughout lactation, and month of the year also having an effect. In conclusion, the use of automated behavior recording enabled thorough investigations of relationships between a range of behavior traits and frequently recorded production traits, and revealed that patterns of change during lactation are strongly affected by breed and parity.

Answer 661

To evaluate the reliability of a 3-point dirtiness scoring system recently conceived for the assessment of the dirtiness present at the lower legs and claws of dairy cows  The 3-point back-view dirtiness scoring grid may offer dairy consultants and farmers a reliable and easy tool for assessing cow foot dirtiness, with excellent scoring consistency and interrater agreement

Answer 662

 Validation work using lactating dairy cow plasma samples showed high sensitivity and specificity for differentiation of samples with ≥1 or <1 ng/mL progesterone, with an overall accuracy of 90%.  The developed portable system may be an alternative tool to existing on-farm methods for determination of reproductive status of cattle

Answer 663

 Interactions between arginine and glutamine supplementation and milk allowance on small intestine morphological development were observed  Increasing milk allowance improved villus height, width, and surface area but only in Arg- or Gln-supplemented calves, not in control calves.

Answer 664

 Prenatal cooled (i.e. no heat stress) calves weighed more at birth and weaning with a tendency for greater average daily gain compared with prenatal heat stressed calves  Postnatal cooled (i.e. no heat stress) calves had increased milk replacer and concentrate intake and a tendency for reduced fever, infection, and total medication events relative to postnatal heat stressed calves  Prenatal heat stress abatement improves weight gain, hematocrit, and immunoglobulin transfer, whereas postnatal heat stress abatement modulates thermoregulatory responses, feed intake, and calf health.

Answer 665

 Calves fed within 1.5hrs of birth 3.79L of:  Maternal colostrum – 106g/L IgG, total 401g IgG fed  LMC – 153g IgG total fed  CR – either 110g or 150g IgG fed.  All treatments resulted in acceptable serum immunoglobulin G values at 24 h.  Efficiency of immunoglobulin G absorption was greater in calves fed colostrum replacer. No differences in growth or health were observed through 7 wk of age. We found no differences in average daily gain or health variables measured, and no differences in final hip width, withers height, or body weight for calves fed MC, LMC-CR, CR-150, or CR-110. These results indicate that CR can be fed successfully as an alternative to MC or as a supplement to colostrum with low IgG.

Answer 666

 Feed restriction (and increases in plasma NEFA, BHB and a decrease in plasma glucose) associated with increased milk glucose-6-phosphate and isocitrate and decreased milk BHB, glucose, glutamate, uric acid and free amino group concentrations.  Feed restriction also associated with decreased milk concentrations of medium chain fatty acids, and increased concentrations of long chain fatty acids.  Milk glucose and glutamate showed the strongest correlations with plasma metabolites and milk FA associated with lipomobilization These results suggest that milk metabolites may be used as noninvasive indicators of negative energy balance and metabolic status of dairy cows.

Answer 667

 Hierarchical Bayesian analysis of the results revealed 3 attributes of equal top importance: (1) access to grazing, (2) cow health and welfare, and (3) cow comfort.

Answer 668

 The results showed little ability to detect the pregnancy status before 150 days of pregnancy  A single model had a ROC of 0.76-0.78 for status after 150d

Answer 669

 Digital cushion thickness varies depending on farm management practices, wither height, sacral height, and body condition score and confirmed that digital cushion thickness varies by stage in lactation and digit.  There is a genetic component to Digital cushion thickness; gene markers may be used for genomic selection to reduce claw horn lesion and lameness events.

Answer 670

 The sensitivity to detect any lesion of digital dermatitis with a single borescope examination in the milking parlor was 55% compared with 79% for a trimming chute examination  When the data were dichotomized into active lesions (M1, M2, M4.1) versus inactive lesions or absence of lesions (M3, M4, M0), the sensitivity and specificity of the borescope were, respectively, 32% (95% CrI 13–58%) and 91%  An isolated borescope examination, especially for diagnosing active DD lesions, has low sensitivity for use as a surveillance method.  For such use, the sensitivity could be improved by repeating the borescope exam on a regular basis.

Answer 671

 Hoof lesions were associated with decreased odds of cyclicity and extended interval to first service.  Cows with infectious lesions and sole hemorrhage in early lactation had smaller odds of first-service pregnancy per artificial insemination and reduced hazard of pregnancy, respectively.  Noninfectious and infectious hoof lesions in early lactation were associated with an extended interval from calving to pregnancy.  Sole hemorrhage accounted for 93% of new hoof lesions that developed between 20 and 120 d in milk. Hoof lesions at D20, but not new HL, were associated with decreased odds of cyclicity, longer interval from calving to first service postpartum, and reduced pregnancy hazard in Jersey cows. The effect of an HL diagnosis in early lactation and management to reduce chronic HL in dairy cows warrants further investigation.

Answer 672

 20% of strains were resistant to penicillin  All strains susceptible to amoxy-clav  There was a low prevalence of antibiotic multidrug resistance in S. aureus isolates.  The most prevalent virulence gene was hla (100%), followed by hlb (84.9%) and sea (65.6%)  Detection of selected antimicrobial resistance genes did not always correspond with the occurrence of phenotypic antibiotic resistance

Answer 673

 Periods of hot weather led to increased time spent at the drinker, frequency of visits, water intake, and competitive events.  Cows with low competitive success at the drinker shifted their drinking behaviour to avoid peak times of day.  Behaviour at the drinker may be useful to indicate when cows feel hot.

Answer 674

 Walking decreased milk yield by 1 kg/milking, truck transport had no effect  milk somatic cell count and plasma nonesterified fatty acids increased after walking and truck transport.

Answer 675

 Klebsiella are often associated with longer intramammary infections and less successful clinical outcomes.  Initial cases of clinical mastitis are caused by heterogeneous populations of isolates, but when intramammary infection persisted, a similar strain was repeatedly isolated from the affected quarter.  Some strains of Klebsiella may cause persistent intramammary infection

Answer 676

 The current study investigated effects of different pre-transport diets (electrolytes vs. rearing milk), transport durations (6 vs. 18 h), and type of truck (conditioned vs. open) on physiology of young veal calves that were received and mixed at a collection center in Germany and transported to a veal farm in the Netherlands.  Short transport duration and provision of milk at the collection center improved energy status of calves and prevented fat mobilization.

Answer 677

 The sex of the calf, volume of colostrum fed, level of calving assistance, and colostrum feeding method were associated with the level of serum total protein. o Male calves had a 0.14 g/dL lower serum total protein than female calves

Answer 678

 Treatment did not alter concentration of total protein in blood serum, prevalence of diarrhoea or other signs of disease, or rate of growth.  Feeding n-3 FA and α-tocopherol increased plasma concentrations of the n-3 FA, including α-linolenic, eicosapentaenoic, and docosahexaenoic acids, with a concomitant decrease in oxidant status index during the first week of life.

Answer 679

 A direct correlation between frequently used antimicrobials and reduced susceptibility could not be determined based on results of the present study.

Answer 680

 The majority of S. uberis IMI in this herd were transient and showed spontaneous cure.  In addition to environmental S. uberis IMI, at least 3 types of contagious IMI S. uberis can be defined: o (1) short duration and likely to have spontaneous cure o (2) long duration and unlikely to have spontaneous cure o (3) wide range of duration of infection and spontaneous cure possible depending on host defense capacity.

Answer 681

 Cows from a control group (without clinical mastitis) had fewer days open, improved pregnancy per first artificial insemination (AI), and decreased pregnancy loss compared with groups with clinical mastitis  Pathogens with major importance to mastitis led to more days open compared with those with minor importance; however, no difference was observed between these groups in pregnancy per first AI and pregnancy loss.  When comparing pathogens in terms of Gram staining status (positive and negative), cows affected by gram-negative bacteria had greater days open, reduced pregnancy per first AI, and increased pregnancy loss. This study shows that different mastitis-causing bacteria can affect the fertility of cows differently. Mastitis events caused by major pathogens and gram-negative bacteria were associated with the greatest decrease in reproductive efficiency.

Answer 682

 Treatment consisted of a cluster remover take-off milk flow threshold of 1.2 (ACR1.2) or 0.8 kg/min (ACR0.8) for 57 d.  Increasing cluster remover take-off milk flow threshold from 0.8 to 1.2 kg/min decreased individual milking duration and alleviated machine-milking-induced short-term changes to the teat tissue without adversely affecting milking performance or somatic cell count.  Modification of the automatic cluster remover settings has the potential to improve parlor efficiency and animal well-being.

Answer 683

 Oligosaccharides are prebiotics that can inhibit pathogenic organisms and might enhance small intestinal immunoglobulin G uptake. Parity differences were detected for 3'-sialyllactose, 6'-sialyllactose, and 6'-sialyllactosamine yield, with Mp yield being greater than Pp over the first 7 d in milk.  Concentrations of 3′-sialyllactose and 6′-sialyllactose are elevated at milkings 1, 2, and 3 after calving compared with mature milk (milkings 8+). These findings demonstrate that colostrum and transition milk contain elevated concentrations of certain OS compared with mature milk and suggest further research should be conducted regarding the potential benefits of OS in colostrum and transition milk when fed to newborn calves.

Answer 684

 High adiposity prepartum lowers the whole-body lipid metabolism response to insulin and causes reduced expression of lipogenic genes in SAT 3 weeks before calving  Reduced lipogenic gene expression results in an insulin-resistant state and is associated with higher mobilization of lipid postpartum

Answer 685

 A new metric, termed “living space,” was defined to describe the additional space availability for dairy cows above that deemed to be a baseline requirement  Large variability was identified between farms in total space available per cow, with a range from 5.4 to 12.7 m2  The majority of farmers perceived lifing space as essential for cow welfare In a linear model to predict the "living space" provided on each farm, geographical location and latent class of farmer attitude were covariates significantly associated with the amount of space provided. This study is the first worldwide to quantify variability in loafing and living spaces for dairy herds; further research is required to evaluate the extent to which variation in quantity and quality of space influences cow health, welfare, and productivity, as well as farm economics and emissions.

Answer 686

 Greater starter digestibility was observed for calves fed LO versus HI in concert with increased fibrolytic bacteria proportions (wk 5) in fecal and rumen samples, which resulted in greater postweaning BW gain and similar BW and frame measurements by 16 wk of age  Rate of MR feeding has a larger effect than the processing of corn in CS on performance, fiber digestibility, and rumen and fecal fibrolytic bacterial communities.

Answer 687

 Regardless of prepartum energy intake, cows fed RPC exhibited less inflammation, as evidenced by decreased rectal temperature and decreased plasma concentrations of haptoglobin and fibrinogen. Collectively, these data indicate that transition cows supplemented with RPC experienced less inflammation.

Answer 688

 When fed at high as opposed to moderate rates, preweaning body weight and hip width gain were greater, but the opposite was true in calves from 56 to 112 d.  Over the 112-d period, calves fed at high rates of milk replacer were 2.4 kg heavier than those fed at a moderate rate but tended to have less structural growth.  Feeding higher MR rates caused calves to partially lose growth advantage during the weaning transition and further decreased BW gain and structural growth in the grower period (d 56 to 112), which could be due to reductions in nutrient digestibility as a result of feeding more MR.

Answer 689

 Dairy cows supplemented with 12.9 g of choline ion/d in a rumen-protected form from 21 d prepartum to 21 d postpartum had improved yields of milk and milk components and increased efficiency of feed utilization in the first 105 d postpartum irrespective of the degree of fatness prepartum  Collectively, these findings indicate that the effects of RPC supplementation during the transition period are independent of the degree of fatness of dairy cows prepartum. The findings also suggest that the effects on productive performance are not necessarily mediated by improvements in markers of metabolic health or reductions in hepatic triacylglycerol.

Answer 690

 Cows assigned to supplementation 4wks prepartum  Increased levels of nicotinic acid increased colostrum quality, and 32 g/d increased feed efficiency in calves.

Answer 691

 Calves fed between 2-4months of age pelleted vs textured starter, ad lib vs restricted forage.  High-starch, low-fiber textured starters supported ≥9% more growth than low-starch pelleted starters.  Restricted feeding of starter with ad libitum long grass hay reduced dry matter intake by 13 to 17%, average daily gain by 20%, and hip width change by 10 to 23% compared with 95% starter blended with 5% chopped hay fed ad libitum  Forage should be fed at a restricted rate to calves from 2 to 4 mo of age to achieve optimal growth.

Answer 692

 Calves fed MR @ 10%BW, supplemented with a pelleted starter +/- Essential oil/prebiotic combo, weaned at 42d and followed until 70d.  Average daily gain, dry matter intake, and feed conversions were greater for calves fed the essential oil combination compared with the control-fed calves.

Answer 693

 Predictions of lameness from milk spectra and additional on-farm variables cannot be used, at this stage, as an indicator trait for actual LMS

Answer 694

 Several pathogen-specific risk factors were identified, which might be useful for customizing control and prevention and better predicting the most likely pathogen before sampling results become available. Risk factors for BCV infection  Detection of M. haemolytica  Increasing herd size  Detection of BCV by antigen ELISA on faeces in the calves last year Risk factors for bRSV infection  Seasonal – more in autumn than winter  Presence of PI-3  Increasing prevalence of resp disease in the calves  Increasing duration of resp disease in the calves Risk factors for H. somni  Calf pen group sizes >5  Sawdust bedding Risk factors for M. bovis  Purchase of cattle  Housing of recently purchased cattle in the same airspace This study identified pathogen-specific risk factors that might be useful for the development of customized control and prevention and for the design of decision support tools to justify antimicrobial use by predicting the most likely pathogen before sampling results are available.

Answer 695

 Note; Healthy cows ruminate 8 to 9 h/d.  DCAD +196mEq/kg DM Vs -9mEq/Kg DM  Rumination rate decreased in all cows around the time of calving.  Rumination rate on the first and second day of lactation was highly correlated with the cow's plasma Ca concentration on the first day of lactation  Normocalcemic cows spent more time ruminating on the first day after calving than subclinically hypocalcemic cows or cows with milk fever

Answer 696

 Classification by causative pathogen type revealed some significant univariate indicators of CM and improved mastitis detection for gram-positive cases and cases in which no pathogen was isolated compared with all CM grouped together. On-farm sensor data may provide an additional screening tool for detecting mastitic cows.

Answer 697

 Dairy calves experience higher on farm mortality rates than nondairy (beef) calves in the first 3 mo of life, with 6.00 and 2.86% mortality rates, respectively.  The 0- to 3-mo death rate at slaughterhouse for male dairy calves has increased from 17.40% in 2011 to 26.16% in 2018, and has remained low (<0.5%) for female dairy calves and beef calves of both sexes.  Mean monthly environmental temperature and month of birth appeared to play an important role in neonatal on-farm mortality rates, with increased temperatures significantly reducing mortality rates  Taking the optimal month of birth and environmental temperature as indicators of the best possible environmental conditions, maintaining these conditions throughout the year would be expected to result in a reduction in annual 0- to 3-mo mortality of 37,571 deaths per year, with an estimated economic saving of around £11.6 million (USD $15.3 million) per annum National cattle registers have great potential for monitoring trends in calf mortality and can provide valuable insights to the cattle industry. Environmental conditions play a significant role in calf mortality rates and further research is needed to explore how to optimize conditions to reduce calf mortality rates in GB.

Answer 698

 Cows with culture-negative mild/moderate clinical mastitis were randomly allocated to ketofen or no treatment.  No difference in risk of clinical cure, relapse, recurrence of CM, or odds of new IMI at 14d or 21d or mean SCC at 14d or 21d.  A single intramuscular injection of ketoprofen as sole treatment for OFC-negative, mild clinical mastitis did not reduce time to clinical cure, relapse or recurrence of clinical mastitis, risk of subsequent intramammary infection, or milk somatic cell count compared with untreated controls.

Answer 699

 Staph. aureus genotypic cluster CLB is a contagious genotype  The adlb gene is a possible marker of contagiousness and was present in 85% of CLB genotypes

Answer 700

 The welfare of young calves may be compromised above a THI of 78 (increased respiratory rate and heart rate)  Calves experience significant heat stress above a THI of 88, as indicated by rectal temperature and salivary cortisol concentrations.

Answer 701

 Compared the quantification of NEFA in 147 plasma samples for the gold standard diagnostic laboratory method and 2 alternative methods: a 96-well plate protocol and a small-scale analyzer.  The alternative methods yielded results comparable with the gold standard.  Both methods exhibited very good ability to detect excessive energy deficit precalving

Answer 702

 Compared the quantification of NEFA in 147 plasma samples for the gold standard diagnostic laboratory method and 2 alternative methods: a 96-well plate protocol and a small-scale analyzer.  The alternative methods yielded results comparable with the gold standard.  Both methods exhibited very good ability to detect excessive energy deficit precalving

Answer 703

 Despite minor differences in circulating progesterone concentration dynamics, intravaginal instillation of PGF2α resulted in similar luteal regression risk, proportion of cows detected in ooestrus, ovulation risk after induction of ovulation with GnRH, and pregnancy per artificial insemination after timed artificial insemination.  Intravaginal instillation of PGF2α may be an alternative route of administration compared with intramuscular injection.

Answer 704

 Ruminal acidosis associated with reduced DMI, lower BW, lower blood heamoglobin and HCT.  Ruminal acidosis symptoms in calves appear similar to those in adult cattle, and the aetiology of the disease seems to follow similar mechanisms

Answer 705

 Heat stress associated with increases in vaginal temperature and respiration rate, and decreases in DMI, MY and MF and MP  Supplementation of rumen protected methionine (1.05g/kg DM) associated with maintenance of MP and MF, without effects on DMI, MY or feed efficiency

Answer 706

 In healthy calves, as the age increased, the umbilical structures decreased in size and their ultrasonographic identification became more difficult. Conversely, in affected calves the umbilical structures did not show the same progressive reduction of external diameters and areas, but had an irregular trend of regression.  Also the colour Doppler ultrasonography showed a significant difference in frequency and percentage of speed-flow in the early days of examination between the 3 groups, with the most reliable results detected from the umbilical arteries.  In our experimental study, omphaloarteritis could be detected at the d 1 colour Doppler exam, with a 100% specificity and a 100% positive predictive value