Dairy- the lactation cycle, feeding managements, physiology of milking synthesis, and milking systems Flashcards
examples of replacement stock
-calves (newborn, pre-weaned)
-heifers (post-weaned/pre-puberty, breeding age, pregnent)
examples of adult dairy herd
-dry cows (far off, close-ip/pre-fresh)
-1st-calf heifers
-mature, lactating cows (fresh, early lactation/peak, mid-lactation, late lactation)
what is the breeding cycle of a dairy cow
-(heifer) bred at 14-16mo
-(heifer) calve at 2yr
-calve
-rebreeding 60-90 days
-dry off cow 305-320d
-60 day dry period
how many days is a cow in milk?
305-320d
how much milk of produced per lactation
-1st lactation=8500kg or 28kg/d
-2nd lactation=10000kg or 33kg/d
-4th lactation 12000kg or 40kg/d
what is the culling mean age
4-5 years
what are the main culling reasons
involuntary: disease, injury, infertility, death
voluntary: low milk, sale of surplus animals
what is the culling rate target
20-30%
what is the order of top culling causes (know top 5?)
-infertility
-mastitis
-low ilk production
-feet/leg problems
-sickness
-udder injury/breakdown
-injury/accident
-old age
-other(bad temperment, slow milker, conformation, difficulty calving, metabolic disease
-unknown reasons
what is the life of calves/heifers
-brith
-colostrum (6-12h)
-weaned at 6-8 weeks
-breeding age (13-15m)
-confirmed pregnant (15-17m)
-1st calf at 22-24m
what happens on a cow lactation curve
-rapid increase in milk
-dry matter intake legs behind
-cow “milks off it back”, loses body weight
-target lactation is 305 days with 60d dry period
-peak lactation occurs 60-90d after calving
-presistency=94-96%
-maximun production at 6-8 years or 4-6 lactations
structure (features) of cows udder
-4 mammary glands
or quarters
-each quarter operates independently
-own streak canal
-rear quarters more developed (produce 60% of milk)
structure if alveolus
-milk secreting cells
-single layer of cells grouped in a sphere (hollow centre [lumen])
-surrounded by blood capillaries & myoepithelial cells
-secretes milk found in lumen
circulatory system of the udder
-blood transports nutrients to the udder (1kg of milk=200-500kg of blood)
-blood also carries hormones
(udder development, milk synthesis, regeneration of secretory cells during dry period)
how is whey proteins in the milk made
-amino acids from the blood
-made into beta-lactoglobulin and alpha-lactlbumin (secratory cells)
-made into whey (alveolus/lumen)
how is casin in the milk made
-amino acids from the blood
-caseins (alpha, betam k) (alveolus)
how is lactose made
-glucose (blood)
-glucose+galactose (from glucose) + alpha-lactalbumin (secretory cell)
-lactose
how is triglycerides, shortchain FA, long chain FA made
-acetate and butyrate fatty acids (blood)
-acetate and butyrate fatty acids + glycerol to both molecs (secratory cell)
-triglycerides, shortchain FA, long chain FA(alveoli)
milking parlour system
-all milking equipment centralized
-cows brough to parlour for milking
-different parlour design
-operatots pit
herringbore parlour
-type of parlour system
-double 4 to double 24
-cows stand at 45 deg to operator pit, minimizes distance
-cows handled in groups, slow milking cows in one group
parallel (side by side) parlour
-cows at 90deg to pit, face away form operator
-access to udder between rear legs, form teats difficult
-shorter distance between udders, more efficient
rotary milking parlour
-cows on a rotating platform, milker outside platform
-not expandable, huge capital investment, 2 or more milkers required
how much can one robotic milker milk
a group of 55-60 cows with ~3x/d milkings
how common are robotic milkers in sk
31 farms; 7VMS, 24 astronaut
best suited for small herds
how do cows enter robot milker
voluntarily, fed concentrates during milking
why do robot milkers lead to some culling
-5-10% of cows must be chased to robot
-poor teat placement
principals of milking
-milking is a team effort (cow, milking machine, milker/operator)
-for complete milk removal (proper pre-stimulation, efficent operation of machine, milker-quick+gentle+efficient+clean)
-consistency is key
what is the milk ejaculation/milk let down
-presence of calf
-fetching cows for milking
-entering the milking parlor, sound, sight of machines
-for-stripping, udder preperation
-proper stimulus essential
-“conditioned reflex”
-important to attach milking unit rapidly for maximum milk production
what hormone plays a role in milk ejaculation reflex/milk let down
-oxytocin
-contraction of myoepithelial cells 20-60 seconds after stimulus
-action lasts 6-8 mins
-blood (oxytocin) decreases rapidly
reasons for inhibition of milk letdown
-milk not released from alveoli
-low milk harvest
-pain, stress, excitement, fear
-adrenal gland releases adrenaline
-constriction of blood vessels in udder
-inhibits contraction of myoepithelial cells
-first calf heifers mostly (oxytocin injection?)
why is it important to clean milking equipment after each use
-necessary to harvest high milk quality
-long shelf life
-limit spread of disease
-maintain cow health
what are good milking practices
-calm and consistent and avoid stressing cows
-emphasis on hygiene
-attach milking machine 1 minute after stimulation to allow for milk letdown reflex to occur (oxytosin)
-handle cows gently
what are essential for good milking management
-pre milking disinfection
-udder stimulation and milk let down
-mahcine attachment and positioning
-post milk disinfection
what are the after milking care procedures
-post teat-dipping (approved teat dip)
-encourage cows to stand after milking
-offer fresh feed
how do you handle collected milk
-cool milk rapidly
-store tank 1-4 celcus in bulk tank
-vital to prevent bacterial growth
how often is milked picked up
every other day of daily-depends on size of bulk tank
where is milk processed in saskatoon
one processing plant- saputo
what happen to every load of milk
-sampled by the truck driver
-samples are tested for protein, fat and lactose at DHI lab
-tested for antibiotic residues, adulteration with water, and somatic cell count
-compositional quality
what is the composition of milk
-85-87% water
-3.0-4.5% fat
-4.5-5% lactose
0.7% minerals (Ca+P)
what are the two major factors affecting the profitability of dairy farms
-production level of cows
-composition of the milk
-multiple component pricing in canada
-18.41kg BF, 2.87/kg protein, 0.82/kg other solids (lactose, minerals)
how is the dairy cows time spent
-13-15 hours resting
-3-5 hours eating
-15 mins drinking
-2-3 hours socializing
-2.5-3.5 hours milking/traveling
what are the eating patterns of a dairy cow
-total of 3-5 hours
-10-13 meals per day when fed free choice
-20-30 mins/meal
total milked rations/complete rations
-most common feeding method
-quantitative blend of all diet ingredients formulated to meet specific nutrient requirements of the cows being fed, mixed thoroughly to prevent seperation/sorting and fed for ad libitum/free choice intake as a single feed
-forages, grains, byproducts, protein supplements, mineral-vitiman premix, feed additives
what are the ways you can deliver TMR
mobile (trailer of truck mounted) and stationary mixer (conveyor belt)
what is the feeding frequency
1x or 2x per day
what is feed bunk stability
-how ling it stays good on the ground
-warm + not stable
ways to push up feed
-hydraulic feed pusher
-juno feed pusher
-skid steer
apoptosis
programmed cell destruction of mammary epithelial cells
dry period
-non lactating period prior to an impending parturition
-optimizes milk production in subsequent lactation
-regeneration of mammary epithelial tissue
-typically 60d in length
-min 45d (if not youll see less mik next lactation)
drying off cows
-withdrawal of grain
-stop milking cows abrupt or switch to 1x milking, then abrupt depending on level of milk produciton
what happens with a lack of withdrawal dry period
causes apoptosis of alveoli
dry cow therapy
-long acting antibiotic
-blanket or select approaches (individual cows or quarters)
-changing now (trating cows only that may be prone to mastitis, or quarter that is prone to it
dry period and mammary involution
-keratin plug forms to act as physical barrier
-with high producing dairy cows it takes weeks to develop
teat sealant
-because it takes weeks for keratin plug to form and bacteria can get in a orberseal; teatseal is put in the teat
-paste which can be squeezed out
when is the calf removed from the dam
after birth or within 24hr
what kind of climate do calves need to be in
dry, draught-free environment
national livestock identification for dairy
-id system for dairy cows
-RFID button on cows right ear
-larger panel in left
-large panel has: reg # unique to animal, herd management # (producers pick)
-even bulls get it
-have to have on in first 7 days
what is transition milk
24-72 hours after birth
in colostrum, transition milk and whole milk which component is the only thing that is higher in whole milk then colostrum
lactose
what are the four management aspects to feeding colostrum
-is the colostrum good quality (amount, type if Ig (IgG(most important to feed calves))
-how much is fed
-when should first colostrum be fed
-how should it be fed
colostrometer
-rapid colostrum test
-250ml, 20-25celcus
-50-140mg IgG/ml (superior, green)
-20-50mg IgG/ml (moderate, yellow)
-<20 mg IgG/ml (inferior, red)
brix value of solution
-measures total solids (sugar) content adapted for on farm use
-2-3 drops of colostrum
-brix value of 22% TS equivelent to [IgG] of 50 mg/ml
how should colostrum be fed
-pail or bottle equiped with a clean nipple
-warm to body temp
-tube feeding
-bottle feeding better with restricted colostrum amounts
-maintain very high standards of hygiene
why is bottle feeding better then tubing
-antibodies absorbed form small intestine
-esophageal grove goes directly to abomasum to small intestine
-only does this on animal that is sucking
