Dairy Cattle Flashcards
(121 cards)
1
Q
CA
A
- leading state for dairy production (Wisconsin 2nd)
- mostly in San Joaquin Valley
- 1500 lactating cows = 3000 total cattle (half milking, half are heifers and dry cows)
- CA provides 19% of total US milk supply
2
Q
Tulare
A
- 27% of CA milk produced in Tulare County
- top 1 out of 5 counties that produce 72.4% of CA milk
- has more cows than PA
3
Q
Industry Trends
A
- increase in herd size and decrease in number of dairies (economy of scale – need to drop fixed costs by having fewer cattle that are more efficient at milk production)
- 97% dairy farms are family-owned
- Dutch and Portuguese (Azores) run 90% of the dairy farms in CA? US?
- decrease in consumption of fluid milk, but demand for other dairy products has incr, so total demand remained the same
- 10% US milk is exported, esp to China (milk powder)
4
Q
Dairy Cow Features
A
- highly adaptable
- intelligent, curious
- like predictable routine
- gregarious (groups)
- grazers (ruminants)
- 1500 lbs weight
- bulls (esp Jersey bulls) are really mean, which is why most dairies have AI, not running bull
5
Q
Robotic Milking
A
- cows like routine
- when they need to be milked, they go into milking parlor, robot milks them, and then they leave
- probably going to replace hand-milking bcs of high labor demand that the latter requires
6
Q
Dairy vs. Beef Cattle
A
- beef: more energy to muscle
- dairy: more energy to milk production
- beef: only enough milk for calves (1-2 gal)
- dairy: 6-7 gal of milk
- beef: stouter, more muscled
- dairy: longer, thinner
- beef: less maintenance and labor
- dairy: more maintenance and labor
7
Q
Bull Calves
A
- sold to calf ranch for 4 mo, then to feedlots
- lot of feedlots w/ Holsteins (black and white)
- not different in taste; Holsteins are high-grade meat
8
Q
Feedlot
A
- steers (castrated males)
- heifers (females before first calf)
- NOT COWS (mature females that have had calves)
9
Q
Lactating Cows
A
- mature cows that have given birth and are lactating
10
Q
Dry Cows
A
- mature cows in between lactation cycles
- of 365 days, 60 days are run dry
11
Q
Bulls
A
- intact males
12
Q
Confinement: Intensive Production System
A
- tie stall: cows attached to pole (not common)
- free stall: 1 spot for ea cow, but they can sit where they want
- cow comfort is priority bcs they lay down for half the day
- free stall barns have roof but no walls to allow air flow
- 3/4 dairies in CA are free stall
- free stall bedding
13
Q
Dry Lot
A
- 1/4 dairies in CA
- may or may not include free stalls
- they don’t have concrete floors, but dirt floored corrals
- manure is deposited and then scraped out
14
Q
Dried Manure
A
- manure falls on floor, accumulates, and is scraped away and placed in pile in sun during summer
- heating manure kills bacteria
- sun kills bacteria outside of pile
- microbes heat inside of pile and kill bacteria inside; microbes also die
- can be used as bedding in dry lot corrals or free stall barns (for lactating cows)
- ORGANIC bedding – means microbes can grow in there
15
Q
Liquid Manure
A
- flushed out of barns
- goes into lagoon
- lagoon is 98% water and 2% total solids
16
Q
Sand
A
- gold standard for bedding
- INORGANIC – microbes won’t grow
- disadvantages: heavy, finite, abrasive to equipment and metal, expensive
- only 10% of dairies use sand
17
Q
Water Beds
A
- very rare
- advantage: water in the water bed can be temperature adjusted and facilitate cooling/warming of the cow
- cows have to get used to it
18
Q
Rubber Mats
A
- used to connect freestall barns to milking barn/parlor
- dairy cows have to walk ~200 yds 3-4 times a day for milking
- if they walk on concrete, hooves will have issues and cow may slip, quickly becoming non-ambulatory
- need flooring that provides traction and prevents slipping, aka rubber mats
19
Q
Measure J in Sonoma County
A
- only dairy farms in CA with extensive management pasture production system are in Sonoma County
- Measure J is a ballot measure about getting rid of concentrated animal feeding operations
- really about ending animal agriculture in Sonoma County
- other dairy pasture production systems are in Oregon
20
Q
Organic Dairies
A
- pasture-raised (major source of forage)
- continuous grazing and exercise
- cannot use pharmaceuticals (chemicals, antibiotics)
- when infected, might have to be sold to non-organic dairies to get animal treated and ensure welfare
- one organic standard for entire US which does not account for different climates, soil conditions, etc.
- standard states that cows have to be on pasture 110 days, which doesn’t work for CA (cows don’t have enough grass to eat for certain periods of time)
- no manure management on pasture
21
Q
Calf Hutches
A
- 8 ft wide, 5 ft deep
- 3 separated calves in hutch for 2 mo
- too much space or too little space for calves is bad, need happy medium
- they get stressed w/ too much space
- high level of care can lower mortality rates to as little as 2% in 80,000-calf farm
22
Q
Why Not Group Calves?
A
- when grouped, dominant calf gets most of the milk
- submissive animals don’t get food they need and die
- thus, grouphousing doesn’t work out well
23
Q
Bull Calves
A
- shipped to calf ranch once born
- raised in calf ranch for 4 mo
- sent to beef feedlots in SoCal
- lot of Holsteins in beef feedlots in SoCal for this reason
- no bulls at most dairy farms, including UCD Dairy, bcs dairy bulls are mean
24
Q
Replacement Heifers
A
- usually raised off-farm/contract-reared
- they are raised on separate ranch and returned when grown so dairy farmers don’t need to incur the cost of non-lactating young cattle
- some families will keep the heifers and raise them themselves
25
Calf Facilities' Environment
- also applies to all dairies in general
- need to be clean, dry, comfortable, safe environment
- free of pathogens
- provide relief from environmental stressors (extreme temps)
- provide fresh air: low in dust and gasses
- be well-lit for cow performance and safety
- have flooring that provides traction and prevents slipping
26
Homeostasis
- maintaining body temperature
- 2/3 of energy consumed daily goes into this
27
Heat Stress
- body temp of cow is less than ambient/outside temperatures
- cows are bad at sweating, so they rely on dissipating heat to the environment
- in heat, cows find shade, wind, water, eat less, lie down on cooler ground
28
Ideal Temps for Cows
- 20-70 degrees F
29
Heat Stress Results
- reduces feed intake
- this is bad bcs less milk production, meat/muscle production
- losing money
30
Solutions to Heat Stress
- use fans or sprinklers
- sprinklers have to hit the skin, so can't use fine misters that just hit cow's coat
- in emergency, drench with water
31
Cutaneous Evaporation
- water evaporating off from the skin
32
Worst Heat Conditions
- humid, warm weather is most stressful
- much harder to lower body temp
- dry heat less stressful than more moderate heat w/ high humidity
33
Heat Exchange
- circulating air cools using convection processes (can gain or lose heat)
- cows radiate heat to sky, esp at night
- heat lost from lungs or thru sweat away from the animal
- heat transfer to ground through conduction (can gain or lose heat)
- cows radiate heat to ground (can gain or lose heat)
34
2006 Heatwave
- bunch of cows died bcs it didn't cool down enough at night for cows to lose heat to sky thru radiation
- malfunction in rendering plant that caused cow carcasses to go to landfills for the first time
35
Rendering Plants
- places where cow body parts not used are made into byproducts
- recycle every body part
- no waste in cow production
- 400+ byproducts
36
Social Environment
- social/herd animals kept in group
- need constant visual contact w/ rest of herd
- overcrowding can be negative
37
Observing Social Interactions
- for signs of estrus (esp lordosis)
- for aggression (aggressive animals may need to be culled)
- to ensure adequate feed intake
38
Normal Cow
- alert; interested in surroundings
- normal grooming activities
- chewing cud while resting
- eating
- lying a lot
- moving easily w/ normal gait
- calm while milking
39
Ruminating
- can ruminate while lying or standing
- the more roughage that's in the diet, the more rumination occurs (why pasture-raised animals ruminate more)
- the more roughage is in the diet, the more methane is produced bcs methane-producing microbes in the rumen like roughage
- more concentrate = less rumination
40
Lying Down
- dairy cows lie down for 12-14 hrs
- need proper resting places to keep cows in high welfare
41
Limping, Back Hunched
- cows try to hide their issues bcs they're prey and don't want the predators (us) to know their weaknesses
- limping and hunched back suggest hoof problem, stylus, metal they've ingested
42
Milking
- comfortable situation
- relieves pressure in udder
- cows go voluntarily to be milked 2-4 times a day
43
Grazing
- grazing does not mean organic
44
Freestall Barns (Final)
- no walls, just roof
- concrete base, sand/manure bedding
- most dairies have freestall barns for lactating cows in CA
- remove manure thru flushing into lagoon or piling up thru scraping
45
Dry Lot Corrals
- where dry cows stay, bcs most health issues occur in transition btwn lactating to dry --> easier to keep an eye on individuals in dry lot corrals
- 1/4 of dairies keep both lactating and dry cows in dry lot corrals
- dirt floors
46
Signs of Pain and Distress
- lethargy (inactive, droopy ears; sunken eyes; cold ears)
- restlessness; increased activity
- lack of appetite
- lack of cud chewing
- abnormal defecation/urination
- incr vocalizations
- they usually don’t want to make themselves noticeable
- tonal quality of vocalizations
- intense rubbing, licking, or scratching of skin
- incr or shallow breathing panting
- guarded posture; abnormal appearance or behavior
47
Indicators of Poor Welfare/Management
- high incidence of retained placenta or footrot
- vet knows conditions of dairy w/out seeing it
- each dairy has a health score
- well-run dairy will have good welfare and few incidences of retained placentas, footrot, etc.
48
Retain Placenta
- calf is born, but placenta is kept inside
- shot of oxytocin given to cow and placenta comes out
49
Potential Sources of Pain
- foot/conformation problems (from hard floors, for ex.)
- arthritic conditions
- calving difficulty (dystocia)
- physical injuries; rough handling (rare, but needs to be reported)
- standard dairy practices (freeze branding for dairies or ear tags; dehorning)
50
Animal Handling
- consistent and predictable (cows like routine and are easy to handle as long as we do things they're used to)
- non-aversive handling practices are best, rough handling always bad
- avoid shouting, using electric prods
- don't rush cows, let them explore new environments
51
Flight Zone
- critical distance btwn animal and handler
- dairies have smaller flight zone (you can get closer) bcs they're used to handling
52
Point of Balance
- cow's shoulder
- can use POB to move cows where you want them (to a chute, esp)
- in front of POB, cow moves back
- behind POB, cow moves forward
- never stand directly behind cow; they kick
53
Vision
- monocular vision (one eye on each side of the head) -- signature build of prey animals
- eyes can see about 320 degrees total
- (humans have bifocal vision - better depth perception)
- cows' only blind spot is directly behind them
- good distance vision
- poor depth perception
- some color vision
54
Calves Right After Birth
- can stand, turn around, and find mom's udders and suckle
- humans have to be guided to breast, only know how to suckle and cry
- cows finding the udder is not a learned behavior, it is innate
- humans are useless in comparison
55
Squeeze Chutes
- minimize distractions -- that makes cow handling really difficult
- minimize shadows, too dark or too bright, miscellaneous items left in view
- Temple Grandin figured this out
- she was autistic, understood how cows felt
- people didn't trust her, but she redesigned some facilities and cow handling became really easy
- now, entire dairy industry still uses those designs
- avoid reaching in between rails and bars
56
Transport
- restrict movement w/in vehicle
- minimize exposure to extreme conditions (heat stress, wind chill)
- make floor non-slip or covered w/ sand and grit
- don't transport non-ambulatory animals -- those either need to be treated or euthanized
57
Calves and Colostrum
- feed w/in 5 hrs of birth, so immunoglobulins can pass thru openings in gut
- gut openings close in 5 hrs so that other pathogens don't enter
- still need to feed colostrum for 2-3 days because colostrum has different nutritive value than regular milk
- calves don't need colostrum from their own mother
- older cows have better colostrum because they've been exposed/developed immunity to more pathogens than younger cows -- more antibodies to pass down and calf gets greater transfer of passive immunity
58
Calf Handling
- dry the hair coat and navel cord
- calves are strong enough to walk without assistance
- avoid transport before 3 days old
- take calves away from the mom; if you leave them with the mom, greater morbidity and mortality rates of calves
- beef calves can be kept with moms w/out negative consequences, but dairy cattle cannot
59
Udder
- milk produced inside alveoli
- branches/ducts connect alveoli to teats
60
Mammary Function
- 2 main hormones:
- oxytocin
- prolactin
61
Oxytocin
- from posterior pituitary gland (the master hormonal gland in the body; size of a bean)
- smooth muscle contraction = parturition (why retained placenta treatment is shot of oxytocin, and why humans are given oxytocin when dystocia occurs
- causes contraction of myoepithelial cells
- incr in oxytocin after cervical distension and suckling
- high progesterone inhibits oxytocin (during pregnancy)
62
Prolactin
- from anterior pituitary gland
- synthesis of milk proteins
- growth of mammary glands
- inhibited by stress and dopamine
- people that say dairy cows are under stress are wrong, bcs stress reduces milk output
63
Milk Letdown: Neural Pathway and Oxytocin
- teats stimulated by suckling of calf, or by stripping done by milker
- teats send neural impulse to brain/hypothalamus
- hypothalamus signals posterior pituitary gland
- posterior pituitary gland releases oxytocin
- oxytocin causes myoepithelial cells in alveoli to contract and release the milk
- milking machines don't suck out the milk, but milk is let down and just comes out
64
Milking a Cow
- takes 5 minutes
- 2-3 times per day
- sometimes 80-100 lbs of milk per cow per day = 45+ L
- in Columbia, due to different management, nutrition, welfare, etc., milk output is 5 L per cow per day
- CA has optimized cow needs and output
65
Bovine Somatotropin (bST)
- synthetic bovine growth hormone
- produced/occurs naturally in any cow from anterior pituitary gland
- 20% more milk
- no differences in milk composition
- if cows aren't fed adequate diets and are stressed, bST may cause health and reproductive problems
66
rbST
- recombinant bST developed by scientists that has same chemical structure as bST
- used to be fed to all cows to counteract decrease in milk production that occurs during lactation cycle of the cow
- milk production peaks on day 60 of lactation, then decr
- rbST was supposed to minimize that decrease
- milk must be free of hormones in CA/be rbST-free by law
67
rBST Controversy
- organic dairies advocated hormone-free milk
- despite FDA, WHO, ADA, and National Institutes of Health reassurances, propaganda resulted in rBST being banned in cows whose milk would be sold as fluid milk
- still rBST-treated cows for cheese, butter, other dairy products' production
- growth hormone does nothing to us bcs we ingest it orally, and those peptides are broken down in our stomachs
- cows get it injected in order for the growth hormone to work
68
Dairy Cattle Stats
- 21-day estrous cycle
- 285-day gestation length (similar to humans)
- ovulation 28-32 hrs after estrus, so need semen on hand at time of ovulation
69
Estrus Period
- 2.5-28 hrs
- 25% of cows have estrus periods of less than 8 hrs
70
Heat Detection
- standing heat
- rumination collar
- observation (not feasible for dairies w/ hundreds or thousands of cows)
- Kamar: attach to tail head, breaks and spreads red paint over white strip when mounted
- tail chalk: easy and cheap; also spreads when mounted
- pedometers: measures cow activity (4x more activity in estrus cow)
- heat watch: 95% heat detection rate
71
Rumination Collar
- tracks rumination times and durations and activity of the cow
- usually rumination and activity equal
- during estrus, rumination decreases and activity increases
- cows are restless, looking for a mate
- $100 per collar, but useful investment
72
Synchronization
- use hormones to synch cows' estrous cycles so that herd is in heat during the same times
- makes detecting/predicting estrus easier and deciding when to breed
- don't have to keep vet techs on hand all the time, only when estrus period starts
- labor restricts heat detection success on larger dairies
- benefits the cow
73
PGF2a
- prostaglandin shots help clear any uterine infections
- PGF2a and GnRH can treat cystic ovaries
74
Cystic Ovaries
- either:
- Corpus luteum (empty follicle) does not regress and results in no signs of heat
- or, dominant follicle does not ovulate (estrus behavior every few days)
75
Combination
- of heat detection and synchronization to optimize reproduction management
76
Estrous Cycle Hormones
- when animal produces estrogen/estradiol, that estrogen is impetus for estrus to occur
- when estrogen peaks, estrus is initiated
- progesterone/pregnancy hormone while pregnant (no estrogen surge)
77
Insemination
- right after estrus is optimal time to inseminate
- if you miss estrus signs, you wouldn't know to inseminate her
- sperm is viable in cattle for 24-30 hrs (longer in humans)
- ova viable for 6-12 hrs after ovulation
- very short time period during which there is viable egg and viable sperm at same location and time
- estrus, then insemination (sperm viable for a day), then ovulation, then ova (viable for 6-12 hrs)
78
PTAs (Predicted Transmitting Abilities)
- producer selects semen by traits needed
- very expensive
- uses indices (Net Merit, TPI)
79
Sexed Semen
- use sperm that leads mainly to XX offspring (don't want male offspring)
- more expensive
- less viable than regular semen
- lower conception rate
- mainly used in heifers
80
Bulls
- proven sires are in the thousands
- can get catalog and pick from bulls w/ different traits
- chosen based on focal areas that need improvement
81
Dairy Cows, Horses, Dogs and Cats
- from 25M dairy cows to 9.2M cows in the US
- 60% more milk production
- cow carbon footprint has decr by 2/3
- 9.5M horses and 180M dogs and cats
- all have environmental footprints
- dogs and cats eat 1/3 of all animal-sourced food produced in the US
82
Checking For Pregnancy
- rectal palpation (35-40 d)
- ultrasound (>= 26 d)
- cows that aren't pregnant are losing money
83
Pregnancy Rates
- 10 eligible cows
- 60% of the cows' heat detected (6 cows)
- 50% conception rate (3 cows pregnant)
- pregnancy rate is 30%
- one of the main culling reasons is failure to get pregnant
- services per conception:
- less than or equal to 2 is a good amount, but sometimes more services required
84
Calving Interval
- period from one calving to the next
- includes:
- lactation for 305 days + 60 d dry period
- voluntary waiting period before breeding cow again
- gestation period of 9 mo
85
Milking
- could milk continuously for years, but milk production goes so low that it's not worth it
- better to have dry period
86
Milk Production Cycle
- calving: day 0
- lactation period: 305 days
- day 60: peak milk
- during lactation period, there is a voluntary waiting period, after which the cow is bred
- 60 d before next calving, dry off period begins
87
Dry Period
- stop milking in order to dry off
- at first, udders swell
- then, milk production stops w/ cessation of stimulus initiating milk letdown
- milk is reabsorbed into cow
88
Transition Period
- from dry to lactating
- cow undergoes physiological (from dry to lactating state), environmental/social (several pen moves), and nutritional (diet change, incr in dry matter intake (DMI) ) changes
- this is a period when a lot of cows can get ill
89
Transition Period Possible Issues
- milk fever
- retained placenta
- ketosis
- displaced abomasums
- farms w/ excellent transition programs are often the most successful
90
Management
- determines reproductive success based on nutrition, environment (heat stress), social (need stable social groups bcs mixing cows up stresses them out), heat detection, synchronization protocols
- each facet of management contributes to better reproduction, longer productive life, less environmental impact, and business success
91
Methane Production
- increases with increasing amount of roughage consumed
- animals on pasture produce the most methane
92
Successful Replacement Program
- living until first lactation (2 yrs)
93
Average Mortality Rate in Calves < 3 mo
- 10-30%
- affected by disease, nutrition, environmental conditions, management
- good management: losses = 5%
94
Average Length of Time Cow Stays in Milking Herd
- 2-3 lactations
- avg lifespan of dairy cows is 4-5 yrs
95
Maternity Pen
- disinfected w/ clean bedding
- for calving cows
- low stress, clean, sanitary
- main time when infections could occur
96
Signs of Approaching Parturition
- 48-72 hrs prior
- swelling of vulva
- relaxation of tissue at tail head (tail head up)
- distended udder (udder starts to fill w/ colostrum and is distended to the side)
- nervousness and separation from rest of herd
- muscular exertion (contractions)
97
Delivery
- if longer than 4-6 hrs, provide assistance
- want as little intervention as possible to prevent pathogen exposure
- more assistance needed for heifers, bcs they're 80% the size of mature cow = smaller birth canal
- if cow doesn't lick calf, dry calf to stimulate circulation and breathing
- dry calf to prevent chilling in cold climates
- paint navel w/ 2-7% tincture of iodine soon after birth to prevent entrance of pathogens
98
Newborns
- most are on their feet w/in 30 mins and nurse w/in 1 hr after birth
- wash and sanitize teats and udder if calf directly nursing (not standard)
- if calf doesn't nurse w/in 1 hr, bottle feed
- best method is to bottle feed all calves to control intake and make sure they're getting high-quality colostrum
- individually house calves to prevent transmission, keep under observation, and manage nutrition
- feed calf 4-6% body weight as colostrum
- 4 qts of colostrum in 24 hrs (2 when born, 2 12 hrs after birth)
99
Placenta
- should be passed by 12 hrs postpartum
- retained placenta (RP) could cause sepsis bcs placenta is organic material that bacteria can get into -- direct path into reproductive tract
- RP infects animals months after, future health and reproductive ability impacted
- could be caused by immune system being unable to expel placenta
100
Holsteins
- 90% of dairy cattle in US, 92% of CA
101
Holstein Birth Weight
- 95 lbs
102
Brown Swiss Birth Weight
- 90 lbs
103
Ayrshire Birth Weight
- 75 lbs
104
Guernsey Birth Weight
- 70 lbs
- yellow-golden white color
- produce more beta-carotene --> produce golden milk
105
Jersey Birth Weight
- 60 lbs
106
Mortality and Morbidity
- 5% death loss if calf removed w/in 2-6 hrs
- 20% death loss if calf stays w/ dam over 24 hrs
- caused by inattentive moms and increased exposure to pathogens
- more time calf spends w/ dam = increased chances of disease
- mortality based on person caring for calves
- calves cared for by members of the family had lower death loss than hired labor
- knowing your animals, their environ, their needs is gonna help w/ long-term health of calves
107
Importance of Colostrum to Newborn Calf
- at birth, calf has little to no resistance to disease
- colostrum is means of transferring immunity via antibodies secreted into dam's colostrum (passive immunity)
- may last for 3-9 mo
- earlier it's given, more antibodies absorbed by gut lining
- helps protect calf until its own immune system produces antibodies
- calf is capable of absorbing antibodies from colostrum for a short time (~24 hrs)
- usually 12 hrs
108
Colostrum vs. Milk
- colostrum is highly concentrated, formative nutrition compared to milk
- more protein (immunoglobulins - antibodies)
- more total solids
- more fat
- less lactose
- more ash (inorganic substrates, minerals, vitamins)
109
Calf Hutches
- 3 connected w/ walls between
- slatted floors for feces
- 2 buckets: milk, water, maybe one for grain
- tops can be opened for air circulation or closed to trap heat
- 1.7M dairy cows in CA
- calves can be raised at calf ranches or heifer raisers and then come back at 1 yr old (primarily used on W Coast)
110
UCD Calves
- studied emissions from calves in hutches vs. group pens
- calves don't produce methane bcs they're not ruminating
- still producing feces and urine that have emissions
111
Weaning Age
- 56-60 days old
- risk of mortality decr past 2 mo bcs now they're able to form their own antibodies; more immunity
- period of expensive and labor-intensive hand-feeding is done
- cost of raising animal decreases
112
Normal Growth Rates in Heifers
- double calves' bodyweight from birth to weaning (2 mo)
- proper frame structure for lactation performance
- by puberty (13-15 mo): want 55% of mature bodyweight
- by first calf (24 mo): want 80% of mature bodyweight
- dependent on breed
113
Holstein Growth Goals
- 1500-1550 lbs when full-grown at 3 yrs
- 800 lbs at puberty (55% mature weight)
- 1300 lbs at first calving (80% mature weight)
114
Replacement Heifers Needed
- dependent on herd culling rate
- 1/3 of herd removed every year due to death, morbidity, wanting heifers w/ better genetic potential
- calf and heifer losses
- need more heifers if calf loss high
- normally, dairy producers save all heifer calves and raise as replacements
- currently, heifer price is astronomical, but market changes constantly
115
Reasons Why Cows Leave Dairy Herd
- production
- reproduction
- is there a better milk-producing animal coming in?
116
Housing Needs for Calves
- shelter from wind
- appropriate for season
- inexpensive to build + economical to operate
- easy to clean and disinfect
- individual housing + feeding
- ventilation to prevent dampness + drafts
117
Breed and ADG Goals
- Holsteins are the biggest, so need to grow the fastest = higher ADG
- Jerseys are the smallest = lower ADG
118
Managing Milking Herd
- high producing cows w/in 305 days have good persistency thru lactation and good peak production
- cows freshening at 2 yrs old will normally increase production 25% in peak years
- average cow milks out in ~5 mins
119
Dry Period Purpose
- allow period of rest before next lactation
- repair and regeneration of udder secretory cells
- development of unborn calf
- leads to increased milk yield in successive lactations
120
Methods of Drying Off
- complete cessation of milking
- incomplete milking
121
Dry Cow Mastitis (Dry Cow Treatment)
- effective cure period vs. normal lactation period
- reduces new infections in dry period (42-48% new udder infections occur during dry period)
