dairy nutrition Flashcards
1
Q
what happens during 305 day lactation
A
- lactation begins after calving
- breeding begins 60 d after calving, most cows become pregnant by 85 to 115 d
2
Q
what is the dry period
A
60 day non-lactation
3
Q
what happens during the dry period
A
mammary gland involution and regeneration prior to next lactation
4
Q
what is the average growth rate
A
1.66 lbs/day
5
Q
what is colostrum
A
- first milk produced for the calf
- contains large quantities of immunoglobulins
- excellent source of energy, protein, vitamin A and D
6
Q
what is the only ingredient in colostrum thats lower vs in whole milk
A
lactose (2.7 in colostrum vs 5 in whole milk)
7
Q
what is the importance of colostrum feeding
A
- no placental transfer of immunity in bovine animals
- absorption of colostrum Ig provides passive immunity
8
Q
what does early ingestion of colostrum provide
A
- fluid for post natal circulatory volume
- energy to maintain body temperature
9
Q
what are the components of colostrum
A
- large amounts of immunoglobulins (IgG)
- leukocytes (cellular immunity)
- growth factors and hormones
10
Q
what are the systemic effects of Ig on immunity
A
- protect against infectious enteric and respiratory diseases
- reduced morbidity and mortality
11
Q
what are the local gastrointestinal effects of Ig on immunity
A
- bind to pathogens prior to absorption
- present in intestinal secretions following absorption
12
Q
what are the two proteins present in colostrum
A
casein and whey proteins
13
Q
what are the proteins dependent on in colostrum
A
protein nutrition of the dam
14
Q
what are absorbed amino acids used for
colostrum
A
protein synthesis as well as gluconeogenesis by the newborn calf
15
Q
what do whey proteins provide
A
readily available source of AA
16
Q
what does casein do
A
clots in abomasum to slow release
17
Q
what is a fair to good indicator of colostrum quality is
A
appearance
18
Q
what does thick and creamy colostrum contain
A
higher in antibodies and solids
19
Q
what does thin and watery colostrum contain
A
lower in antibodies, solids (protein, fat)
20
Q
what is a colostrometer
A
- superior (50-140 mg/ml)
- moderate (20-50 mg/ml)
- inferior (<20 mg/ml)
21
Q
about how much of ingested immunoglobulins are absorbed when colostrum is fed immediately after birth
A
35%
22
Q
what are factors affecting passive transfer IG
A
- IgG intake(g) = colostrum (IgG)
- efficiency of absorption of Ig fed (time after birth)
23
Q
what are the guidelines for feeding colostrum
A
- feed 4 quarts of colostrum within 4 hours
- adequate transfer Ig will occur in 90% of calves
- feed 2 quarts again in 12 hours
24
Q
what percent of body weight should you bottle feed colostrum
A
10-12% of body weight
25
esophageal feeder
* slowly pass the tube along the tongue to the back of the mouth
* calf will start chewing and swallowing
26
what is serum refractometer
* calves 1st week
* centrifuge serum
* leave in car 2-4 hr
27
within the first week of life, total protein in ____ calves should be > ____ if <5.0 mg/dl FPT
90%; 5.5 mg/deciliter
28
what are the costs associated with FPT
* increased mortality
* increased treatment costs
* decreased growth rates and feed efficiency
* increased age at first calving
* decreased in 1st and 2nd lactation milk yields
29
how are calves at birth non-ruminants structurally
* rumen-reticulum complex is undeveloped
* esophageal groove diverts milk into abomasum
30
how are calves at birth non-ruminants physiologically
* calves dependent on milk sugars, milk protein and milk fat
* diets are whole milk or milk based replacers
31
what are options for milk feeding
* milk replacer
* whole milk from farm
* waste milk from treated or high SCC cows (unpasteurized, pasteurized, acidified with formic or acetic acid)
32
where are milk protein sources primarily from
by-products of the cheese and butter industry
33
what do milk replacers typically contain
lard or tallow
* emulsified with lecithin to improve mixing and digestibility
34
how digestible is milk fat
96%
35
do highly unsaturated fats give good results
no (soy oil or corn oil)
36
what is the concentration of fat in milk replacers
10-20%
37
how much lactose should replacers contain
40-50%
38
what simple CHO can calves digest
lactose and glucose
39
how much milk or milk replacers should be fed daily
8-10% of body weight daily
40
when should calves be offered grain
around 3 days - as calf grows increase intake of grain
41
what is the goal by weaning (8wks)
double birth weight
42
how many gallons/day are many calves fed milk/replacer
up to 2.5 gallons/day
* feed more milk as galf grows
* grain intake is delayed due to extra milk feeding
43
what is thermal neutral zone
* 60-80 degrees F for calves < 21 days of age
* after 21 days of age lower critical temp is 40 d F
* keep dry and draft free
44
additional energy in milk is needed to maintain body temp - what is the temp and energy
60 d F needs 0.022 Mcal/kg^0.75/degrees C
45
what is the relationship between amount of milk consumed and the amount of calf grain eaten
inverse relationship
46
what is the rumen muscle and epithelium dependent on
dry feed intake of grain
* butyrate stimulates development of rumen papillae
47
what is key in successful weaning
rumen development
48
what is the transition period
2 weeks before and 2 weeks after weaning
49
what should calves consume for 3-4 days before weaning
1kg of starter daily
50
what happens to starter consumption after weaning
increases rapidly and should be offered free choice
51
what is water intake related to
intake of calf grain
(4lbs of water per 1lb starter)
52
in the calf's first 2 weeks of life what is it being fed
* protein % is 27% if on whole milk
* protein % on milk replacers is whatever is reported
53
remainder 6 weeks feeding calves
* grain consumed increases weekly
* protein % declines gradually as more 20% CP grain eaten
54
feeding after weaning and early intro to group pen
protein 20% only calf grain consumed
55
grass hay feeding calves
* consumed at 12% CP
* protein % begins to decline gradually as more hay eaten
56
group pens
* after weaning, moved into super hutch or group pen
* 2-4 months of age
* 180-300 lbs
* limit grain 6-8 lbs/head
* good quality grass hay available free choice
* protein ~18%
57
when weaning to 400lbs, what is period of adaptation
* changes in housing and feeding
* adjustments in rumen fermentation and digestion
58
what are the nutrient requirements at weaning to 400lbs
* calves require high energy and protein feeds
* calf grower with good quality grass hay
59
what occurs before 4 months of age
* forage limited and grain fed until the rumen is fully developed
* beginning to ferment feeds in the rumen
* energy and protein needs mainly from grain
60
what occurs after 4 months of age
* forage in diet continues to increase with heifer age and size
* energy and protein needs shift to rumen microbial fermentation
* VFAs and microbial protein
61
what occurs during pre-calving
* pregnant heifers and cows need to be separated 3 wks before calving and fed a pre-fresh ration
* majority of fetal growth occurs in the last 2 months (fetus needs AA as energy source, fetus growth has priority over maternal growth)
* animals need diets to support any growth needs, the growth of the fetus and growth of mammary gland
62
what is the metabolizable protein requirement for a far-off dry cow (27-32 lbs DM)
* 800 grams/day
* 12-13% CP
63
what is the MP for a pre-fresh dry cow (21-25 lbs DM)
* 1100 grams min at calving
* 15-16% CP
* lysine: methionine ratio close to 3.0
64
how much milk is produced per day
* 60-100lbs of milk/cow/day
* 7-12 gallons of milk per cow per day
65
which lactation has the greated milk production
3rd > 2nd > 1st
66
what is optimal harvesting
* harvest triticale and rye at optimal maturity
* should be in flag leaf/seed head in boot stage
67
what should the length of corn silage be cut to
* 5/8 to 3/4 inch if kernel processor
* KP rolls are set to 1-3 mm between rolls
68
what occurs if there is a protein deficiency
* reduced milk
* reduced fertility
* reduced dry matter intake
69
what occurs if there is excessive protein
* costly
* high ammonia concentrations in rumen, increasing blood ammonia concentration, detrimental to fetility
* detoxification into urea lost in urine, costing energy, environmentally harmful
