JDS February 21 - March20 Flashcards

Question

Effect of duration of exposure to diets differing in dietary cation-anion difference on Ca metabolism after a parathyroid hormone challenge in dairy cows Vieira-Neto et al., 2021

Answer 1

- A metabolic acidosis was detected 24hrs after treatment started in the negative DCAD group - 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 2

- 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 3

- 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 4

- 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 5

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

Answer 6

- 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

Answer 7

- 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 8

- 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 9

- 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.

Answer 10

- 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 quarter Milk Yield were observed between quarters having a persistent IMI or transient IMI with S. chromogenes or with the other NAS species compared with noninfected quarters, despite the higher quarter SCC

Answer 11

- 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 12

- 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

Answer 13

- 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 14

- 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 15

-- 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 16

- 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 17

- 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 18

- 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 19

- 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 20

- Quarters of a typical udder are unequal in milk yields and milking duration. Due to potentially large differences in milking duration between quarters, this study sought to evaluate changes in milk-flowrate for removal of the last quarter teatcup. - 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 21

- Administration of 1α,25-dihydroxyvitamin D3 within 6 h of parturition successfully induced an acute and transient increase in concentrations of calcitriol in plasma for the first 3 d postpartum, which resulted in a sustained increase in plasma concentrations of iCa, tCa, and tP in the first 5 d postpartum. - Collectively, results from the current experiment indicate that treatment with either 200 or 300 μg of 1α,25-dihydroxyvitamin D3 immediately after calving is an alternative method to reduce hypocalcemia, but health benefits depend on the cohort of cows treated

Answer 22

- 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 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.

Answer 23

- 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 24

 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 25

 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

Answer 26

 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 27

 Short gestation length was a greater contributor to poor performance than dry period length itself  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.

Answer 28

 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 29

 Serum IgG concentrations were higher and more persistent in calves fed colostrum or a mixture, compared to those fed whole milk

Answer 30

 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 31

 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 32

 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.

Answer 33

 Plasma L-lactate concentrations determined upon admission to the hospital, pre surgery, 6, 12, 24, 48, 72hrs later.  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.

Answer 34

 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 35

 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

Answer 36

 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 37

 Calves examined twice weekly and disease classified as: 29%- Upper respiratory tract disease – clinical signs, no consolidation 43% -Subclinical lobular pneumonia – no clinical signs, patchy consolidation ≥1 cm2 13%-Clinical lobular pneumonia – clinical signs, patchy consolidation ≥1 cm2 8%-Subclinical lobar pneumonia – no clinical signs, ≥1 lobe consolidated 7 % Clinical lobar pneumonia - clinical signs, ≥1 lobe consolidated  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.

Answer 38

 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)

Answer 39

 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.

Answer 40

 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.

Answer 41

 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 42

 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 43

 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 44

 Diets  Low protein: 14% CP at peak lactation, 13% CP at late lactation  High protein: 18% CP at pea lactation, 16% CP at late lactation  Some high-producing cows are better able to maintain high production when fed less protein.  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 45

 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 46

 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

Answer 47

 4 treatment groups, weaning at 56d by gradual method:  Low milk allowance (4L/day), finely ground starter  Low milk allowance (4L/day), textured starter (incl. steam-flaked grains)  High milk allowance (Up to 10L/day), finely ground starter  High milk allowance (Up to 10L/day), textured starter (incl. steam-flaked grains 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 48

 Thus, earlier induction of ovulation relative to TAI with sexed semen decreased pregnancies per artificial insemination in primiparous Holstein cows.

Answer 49

 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 50

 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 51

 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 52

 Greater genomic merit for daughter pregnancy rate is associated with shorter interval from calving to first oestrus and greater intensity of oestrus.  Despite not being associated with pregnancy per service, genomic merit for daughter pregnancy rate was positively associated with the hazard of pregnancy

Answer 53

 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 54

 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)

Answer 55

 Defined a 4-level scoring scale: Score Faecal DM content 0 = normal (firm but not hard); 25% 1 = soft (does not hold form, piles but spreads slightly); 22% 2 = runny (spreads readily); 16% 3 = watery (liquid consistency, splatters). 11%  Using observational fecal consistency scoring can accurately predict diarrhoea or a decline in fecal DM.

Answer 56

 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.

Answer 57

 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 58

 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 59

 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 60

 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 61

 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 62

 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

Answer 63

 2-3wk old dairy calves healthy, but “at high risk” of developing BRD were untreated, or administered a single dose of enrofloxacin or tulathromycin  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 64

 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 65

 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 66

 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 67

 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 68

 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 69

 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

Answer 70

 Max intake 0.85 kg/d split in two feedings. Ad libitum access to water and 25% CP pelleted calf starter.  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 71

 Calves housed individually, ad lib solid feed and water, fed 6L milk from d3-10, then 4 treatment groups:  8L/day to 28d, then 4L/d from 29-63d  8L/day to 42d, then 4L/d from 43-63d  8L/day to 56d, then 4L/d from 57-63d  8L/day to 63d, abruptly weaned  Starter intake was greatest in calves in the 28d x 8L/day group  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 72

 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 73

 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.

Answer 74

 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 75

 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 76

 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

Answer 77

 Meta-analyses were performed on 6 risk factors: herd type, herd size, participation in shows or markets, introduction of cattle, grazing, and contact with other cattle herds on pasture  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 78

 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. -We concluded that motivation to walk affects several gait attributes of dairy cows

Answer 79

 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

Answer 80

 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

Answer 81

We conclude that heat treatment of colostrum is associated with a reduction in the concentration of bacterial counts (93%) and SCC (36%), IgA (8.5%), insulin, and IGF-I. In addition, proteomics analysis of colostral whey identified several complement components and other proteins that decreased in abundance due to heat treatment. Although IgG concentrations were unaffected and a reduction in bacterial counts was achieved, the change in several immunologically active proteins and growth factors may have biologically important effects on the developing immune system of the neonate fed heat-treated colostrum.

Answer 82

 Decreased abundances in calves fed heat-treated colostrum included several enzymes relating to carbohydrate metabolism, involved in glycolysis or glycogenolysis.

Answer 83

 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 84

 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 85

 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.

Answer 86

 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).

Answer 87

 Rectal temperature was not significantly correlated with ear, Subcutaneously in the Upper Scapula (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 88

 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

Answer 89

 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 90

 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.

Answer 91

 higher milk leakegae cows with ISCc more 200.000 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 92

 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 93

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

Answer 94

 Three treatment groups, started at dry off 60d pre calving o Low energy: NRC minimum: 5.6 MJ of net energy for lactation/kg DM o High energy: 6.7 MJ of net energy for lactation/kg DM o Low, then high energy: low for the first 21, then high for the second 21d  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.  Indeed, the increased liver fat accumulation and prolonged elevation of BHB postpartum suggests that this approach might actually increase metabolic risk to cows postpartum

Answer 95

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

Answer 96

 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 97

 Feeding grass hay reduced weight gain, but all calves achieved a level of gain to meet growth goals for breeding  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 98

 After first colostrum feeding after birth, calves assigned to receive whole milk, 50% colostrum and 50% whole milk, or 100% colostrum q12hrs for 3d.  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 99

 Starting from birth, calves either received a daily supplementation of Saccharomyces cerevisiae boulardii CNCM I-1079for 7d  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 100

 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 101

 Heat stress impairs overall mammary gland turnover during the dry period, which then affects secretory activity and productivity in the next lactation.

Answer 102

 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 103

 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 104

 Evaluated behaviour of calves injected with cornual lidocaine or saline approach on behaviours 11d after hot iron disbudding  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 105

 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(PP) 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 106

MOK023 (CC97) Cows developed Subclinical mastitis Cows developed MOK124 (CC151) Clinical mastitis Milder reduction in milk yield 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 107

 Cows treated with ASA had lower metabolic stress compared with untreated cows, and cows in second or greater lactation tended to produce more milk during the first 60 d after calving.  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 108

 Calves fed ad-lib started and 8L/day pasteurized waste milk assigned at 14d to:  Stationary brush  Chopped bermudagrass hay  Both of the above  Neither of the above  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 109

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 110

 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 111

 A convenience sample of 109 dairy farms in Ontario were visited from June to August 2019  24% of calves had FTP.  Risk of FTP not associated with age or sex

Answer 112

 Staphylococcal enterotoxin M may be associated with mastitis.

Answer 113

 Phantom cows are defined as cows that have been artificially inseminated <15 after Mating Start Date (MSD), 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 114

 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 115

 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 116

 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 117

 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 Short Chain Fat Acid (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 118

 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 119

 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 120

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)

Answer 121

 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 122

 Diets fed from 21d pre calving to +28d after calving. RPG fed at 5.3% DM  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 123

 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 124

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

Answer 125

 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 126

 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 127

 No treatment, lidocaine cornual, meloxicam, lidocaine plus meloxicam  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 128

Overall, cows with fever showed behavioral changes such as decreased feeding time that are consistent with sickness responses described in other species.

Answer 129

 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 130

 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 131

 2x BDCT groups and two quarter level SDCT groups:  ABS alone to all quarters  ABS + Internal Teat Sealant (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 132

 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 133

 This study examined the effect of delivering the diet once, twice, or 4 times daily  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 134

 4 treatment groups for the last 28d before calving combining  High or low DCAD - +6mEq/100g DM or -24mEq/100g DM  High or low dietary Ca: 2% DM or 0.4% DM  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 135

 Calves were randomly assigned to 1 of 5 levels of glucose inclusion (replacing lactose) up to 30%  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 136

 Tryptophan a precursor of serotonin, was hypothesized to alleviate weaning stress  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 137

 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 138

 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 139

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

Answer 140

 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 141

 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 142

 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 143

 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 144

In a multi-site, randomized, natural exposure trial,culture- and algorithm-guided SDCT each reduced antibiotic use without having a negative impact on cow health and performance, including risk for clinical mastitis, risk for removal from the herd, and DHIA measures of SCC and milk yield during the first 120 DIM. These findings indicate that SDCT can be successfully implemented on appropriate commercial dairy herds in the United States.

Answer 145

In a multi-site, randomized, natural exposure, non-inferiority trial, culture- and algorithm-guided SDCT each reduced antibiotic use by 55% without having a marked effect on risk of IMI cure and new IMI during the dry period and IMI prevalence at 1 to 13 DIM. The findings from this study and others indicate that SDCT can be successfully implemented on appropriate commercial dairy herds in the United States.

Answer 146

 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 147

 The final model could accurately predict blood plasma NEFA concentrations <0.6 mmol/L, where it underestimated the true level of blood plasma levels >1.2mmol/L  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 148

 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.

Answer 149

 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 150

 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 151

 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 152

 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 153

 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 154

 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 155

 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 156

 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 157

 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 158

 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 159

 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 160

 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 161

 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 162

 4 methods:  Conductive cooling mats under the sand bedding  Convective cooling at the feedbunk and lying areas  Evaporative cooling with spray nozzle and fans at the feed areas and fan over the freestalls  Evaporative cooling with half the amount of spray water and fan at the feedbunk  Mats were ineffective  The most effective and efficient method was co-location of the spray water and fan at the feed bunk

Answer 163

 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 164

 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 165

 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:

Answer 166

 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 product 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 167

 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 168

 Calves fed within 1.5hrs of birth 3.79L of:  Maternal colostrum – 106g/L IgG, total 401g IgG fed  LowMaternal Colostrum quality (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.

Answer 169

 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 170

 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 171

 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 172

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 The findings of this investigation revealed that coefficients for interrater agreement (0.38, 0.62 and 0.63) and rating concordance (0.55, 0.75 and 0.74) of back-view scorings improved over time and were superior or similar to those obtained from lateral-view evaluations (coefficients for interrater agreement = 0.20, 0.35, and 0.69; coefficients for rating concordance = 0.48, 0.59, and 0.78). Additionally, the scoring consistency of the raters using the back-view grid was excellent (Cronbach's α = 0.93)

Answer 173

 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.

Answer 174

 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 175

 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 176

 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 177

 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 178

 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 179

 Increasing fat content at the expense of lactose decreased calf milk replacer (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 180

 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.  These results suggest that producers may feed colostrum or transition milk past 24 h postnatal to benefit neonatal intestinal development.

Answer 181

 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

Answer 182

 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 loafing space as essential for cow welfare

Answer 183

 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 184

 Oligosaccharides are prebiotics that can inhibit pathogenic organisms and might enhance small intestinal immunoglobulin G uptake  Concentrations of 3′-sialyllactose and 6′-sialyllactose are elevated at milkings 1, 2, and 3 after calving compared with mature milk (milkings 8+).

Answer 185

 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 186

 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.

Answer 187

 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 188

 A direct correlation between frequently used antimicrobials and reduced susceptibility could not be determined based on results of the present study. The German S. aureus isolates investigated in the present study were inhibited at comparatively higher MIC90 values for most β-lactams than isolates from Danish dairy farms. The blaZ and mecA resistance genes were isolated in individual German S. aureus isolates only and were generally associated with comparatively higher MIC values

Answer 189

 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 190

 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 191

 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 192

 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 193

 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 194

 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.  In exploratory analysis, we found that cows with low competitive success at the drinker shifted their drinking behavior to avoid the drinker at the hottest and most competitive time of day  Behaviour at the drinker may be useful to indicate when cows feel hot.

Answer 195

 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 196

 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.

Answer 197

 The reference standard test to diagnose DD is visual observation in a trimming chute, which cannot be practically performed daily on dairy farms.  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.

Answer 198

 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 199

 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 200

 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 201

 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

Answer 202

 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.

Answer 203

 Heat stress associated with increases in vaginal temperature and respiration rate, and decreases in DMI, MY and Milk Fat and Milk Protein  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 204

 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 205

 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 206

 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 207

 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 208

 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 209

 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

Answer 210

 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.  Sensitivity was greater for detecting GN when the baseline was closer to the day of diagnosis (d −3), whereas Se was greatest for detecting GP and NPI when data up to 10 d before clinical diagnosis were included in models

Answer 211

 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 212

 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 213

 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 214

 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 215

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

Answer 216

 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  Effects on productive performance are not necessarily mediated by improvements in markers of metabolic health or reductions in hepatic triacylglycerol.

Answer 217

 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 218

 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.

JDS February 21 - March20 Flashcards

(243 cards)