Dairy- the lactation cycle, feeding managements, physiology of milking synthesis, and milking systems

Question 1

examples of replacement stock

Answer 1

-calves (newborn, pre-weaned)
-heifers (post-weaned/pre-puberty, breeding age, pregnent)

Question 2

examples of adult dairy herd

Answer 2

-dry cows (far off, close-ip/pre-fresh)
-1st-calf heifers
-mature, lactating cows (fresh, early lactation/peak, mid-lactation, late lactation)

Question 3

what is the breeding cycle of a dairy cow

Answer 3

-(heifer) bred at 14-16mo
-(heifer) calve at 2yr
-calve
-rebreeding 60-90 days
-dry off cow 305-320d
-60 day dry period

Question 4

how many days is a cow in milk?

Answer 4

305-320d

Question 5

how much milk of produced per lactation

Answer 5

-1st lactation=8500kg or 28kg/d
-2nd lactation=10000kg or 33kg/d
-4th lactation 12000kg or 40kg/d

Question 6

what is the culling mean age

Answer 6

4-5 years

Question 7

what are the main culling reasons

Answer 7

involuntary: disease, injury, infertility, death
voluntary: low milk, sale of surplus animals

Question 8

what is the culling rate target

Answer 8

20-30%

Question 9

what is the order of top culling causes (know top 5?)

Answer 9

-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

Question 10

what is the life of calves/heifers

Answer 10

-brith
-colostrum (6-12h)
-weaned at 6-8 weeks
-breeding age (13-15m)
-confirmed pregnant (15-17m)
-1st calf at 22-24m

Question 11

what happens on a cow lactation curve

Answer 11

-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

Question 12

structure (features) of cows udder

Answer 12

-4 mammary glands
or quarters
-each quarter operates independently
-own streak canal
-rear quarters more developed (produce 60% of milk)

Question 13

structure if alveolus

Answer 13

-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

Question 14

circulatory system of the udder

Answer 14

-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)

Question 15

how is whey proteins in the milk made

Answer 15

-amino acids from the blood
-made into beta-lactoglobulin and alpha-lactlbumin (secratory cells)
-made into whey (alveolus/lumen)

Question 16

how is casin in the milk made

Answer 16

-amino acids from the blood
-caseins (alpha, betam k) (alveolus)

Question 17

how is lactose made

Answer 17

-glucose (blood)
-glucose+galactose (from glucose) + alpha-lactalbumin (secretory cell)
-lactose

Question 18

how is triglycerides, shortchain FA, long chain FA made

Answer 18

-acetate and butyrate fatty acids (blood)
-acetate and butyrate fatty acids + glycerol to both molecs (secratory cell)
-triglycerides, shortchain FA, long chain FA(alveoli)

Question 19

milking parlour system

Answer 19

-all milking equipment centralized
-cows brough to parlour for milking
-different parlour design
-operatots pit

Question 20

herringbore parlour

Answer 20

-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

Question 21

parallel (side by side) parlour

Answer 21

-cows at 90deg to pit, face away form operator
-access to udder between rear legs, form teats difficult
-shorter distance between udders, more efficient

Question 22

rotary milking parlour

Answer 22

-cows on a rotating platform, milker outside platform
-not expandable, huge capital investment, 2 or more milkers required

Question 23

how much can one robotic milker milk

Answer 23

a group of 55-60 cows with ~3x/d milkings

Question 24

how common are robotic milkers in sk

Answer 24

31 farms; 7VMS, 24 astronaut
best suited for small herds

Question 25

how do cows enter robot milker

Answer 25

voluntarily, fed concentrates during milking

Question 26

why do robot milkers lead to some culling

Answer 26

-5-10% of cows must be chased to robot
-poor teat placement

Question 27

principals of milking

Answer 27

-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

Question 28

what is the milk ejaculation/milk let down

Answer 28

-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

Question 29

what hormone plays a role in milk ejaculation reflex/milk let down

Answer 29

-oxytocin
-contraction of myoepithelial cells 20-60 seconds after stimulus
-action lasts 6-8 mins
-blood (oxytocin) decreases rapidly

Question 30

reasons for inhibition of milk letdown

Answer 30

-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?)

Question 31

why is it important to clean milking equipment after each use

Answer 31

-necessary to harvest high milk quality
-long shelf life
-limit spread of disease
-maintain cow health

Question 32

what are good milking practices

Answer 32

-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

Question 33

what are essential for good milking management

Answer 33

-pre milking disinfection
-udder stimulation and milk let down
-mahcine attachment and positioning
-post milk disinfection

Question 34

what are the after milking care procedures

Answer 34

-post teat-dipping (approved teat dip)
-encourage cows to stand after milking
-offer fresh feed

Question 35

how do you handle collected milk

Answer 35

-cool milk rapidly
-store tank 1-4 celcus in bulk tank
-vital to prevent bacterial growth

Question 36

how often is milked picked up

Answer 36

every other day of daily-depends on size of bulk tank

Question 37

where is milk processed in saskatoon

Answer 37

one processing plant- saputo

Question 38

what happen to every load of milk

Answer 38

-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

Question 39

what is the composition of milk

Answer 39

-85-87% water
-3.0-4.5% fat
-4.5-5% lactose
0.7% minerals (Ca+P)

Question 40

what are the two major factors affecting the profitability of dairy farms

Answer 40

-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)

Question 41

how is the dairy cows time spent

Answer 41

-13-15 hours resting
-3-5 hours eating
-15 mins drinking
-2-3 hours socializing
-2.5-3.5 hours milking/traveling

Question 42

what are the eating patterns of a dairy cow

Answer 42

-total of 3-5 hours
-10-13 meals per day when fed free choice
-20-30 mins/meal

Question 43

total milked rations/complete rations

Answer 43

-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

Question 44

what are the ways you can deliver TMR

Answer 44

mobile (trailer of truck mounted) and stationary mixer (conveyor belt)

Question 45

what is the feeding frequency

Answer 45

1x or 2x per day

Question 46

what is feed bunk stability

Answer 46

-how ling it stays good on the ground
-warm + not stable

Question 47

ways to push up feed

Answer 47

-hydraulic feed pusher
-juno feed pusher
-skid steer

Question 48

apoptosis

Answer 48

programmed cell destruction of mammary epithelial cells

Question 49

dry period

Answer 49

-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)

Question 50

drying off cows

Answer 50

-withdrawal of grain
-stop milking cows abrupt or switch to 1x milking, then abrupt depending on level of milk produciton

Question 51

what happens with a lack of withdrawal dry period

Answer 51

causes apoptosis of alveoli

Question 53

dry cow therapy

Answer 53

-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

Question 54

dry period and mammary involution

Answer 54

-keratin plug forms to act as physical barrier
-with high producing dairy cows it takes weeks to develop

Question 55

teat sealant

Answer 55

-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

Question 56

when is the calf removed from the dam

Answer 56

after birth or within 24hr

Question 57

what kind of climate do calves need to be in

Answer 57

dry, draught-free environment

Question 58

national livestock identification for dairy

Answer 58

-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

Question 59

what is transition milk

Answer 59

24-72 hours after birth

Question 60

in colostrum, transition milk and whole milk which component is the only thing that is higher in whole milk then colostrum

Answer 60

lactose

Question 61

what are the four management aspects to feeding colostrum

Answer 61

-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

Question 62

colostrometer

Answer 62

-rapid colostrum test
-250ml, 20-25celcus
-50-140mg IgG/ml (superior, green)
-20-50mg IgG/ml (moderate, yellow)
-<20 mg IgG/ml (inferior, red)

Question 63

brix value of solution

Answer 63

-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

Question 64

how should colostrum be fed

Answer 64

-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

Question 65

why is bottle feeding better then tubing

Answer 65

-antibodies absorbed form small intestine
-esophageal grove goes directly to abomasum to small intestine
-only does this on animal that is sucking