Dairy 1

Question 1

top 2 provinces for dairy production

Answer 1

QB, ON

Question 2

primary goal of any nutrition program is

Answer 2

formulate diets that meet the nutrient requirements of animal

Question 3

what do we need to know to formulate balanced diets, 4 things

Answer 3

environment of animal, nutrient requirements, DMI, feed ingredient composition

Question 4

average production per cow in Canada is

Answer 4

10,675 L per lactation (this is dry period of 60 days and then lactation of 305 days)

Question 5

what 3 physiological processes contribute to energy and protein pool

Answer 5

internal digestibility, rumen fermentation

Question 6

what is energy and protein pool used for, 5 things

Answer 6

maintenance,ce pregnancy, lactation, growth, reserves

Question 7

what is gross energy (GE)

Answer 7

the total amount of chemical energy in the diet consumed

Question 8

what is digestible energy (DE)

Answer 8

the amount of energy in the feed minus the amount of energy lost in the feces

Question 9

what is metabolizable energy (ME)

Answer 9

the amount of energy in the feed minus the energy lost in the feces, urine, and gaseous (methane) loss

Question 10

what is net energy (NE)

Answer 10

amount of energy in feed minus energy lost in feces, urine, gases, heat production; can be thought of as net energy for maintenance (NEm) and net energy for production (NEp, which is equal to RE)

Question 11

what is first limiting factor concept (Sprengel-Liebig law of minimum)

Answer 11

growth is controlled not by the total amount of resources available, but by the scarcest resource.

Question 12

what is retained energy (RE)

Answer 12

Retained energy (RE) is defined as the energy stored in body tissues or secretions, including feathers and eggs.

Question 13

what forage quality do dairy production systems need

Answer 13

high quality

Question 14

how do dairy calves acquire passive immunity and what is the cutoff for failure of passive transfer

Answer 14

colostrum, target is 10 mg/mL in calf serum IgG (remember in beef calves the cutoff is 24 mg/mL IgG)

Question 15

compared to dairy cows, dairy heifers have higher or lower IgG content of colostrum

Answer 15

lower

Question 16

tell me about colostrum composition

Answer 16

contains essential nutrients, antibodies, hormones, growth factors; first 2-3 weeks of life critical, composition changes to milk rapidly, should contain minimum 50 mg/mL IgG

Question 17

what are 5 negative outcomes of failure of passive transfer

Answer 17

higher pre-weaning morbidity and mortality (4x increase in death rate), decreased weaning weight, decrease ADG to 180d, decreased milk and fat production at first lactation, delayed time to calving

Question 18

considering that IgG absorption declines rapidly after first, what do we need to ensure for calves

Answer 18

need to feed calves colostrum before 6h to achieve serum IgG levels > 10 mg/mL (because IgG absorption declines rapidly in first 4 milkings and IgG absorption declines rapidly after birth)

Question 19

how much IgG does a calf need to consume to achieve at least 10 mg/mL in serum?

Answer 19

depends on weight of calf, but 80-100 GRAMS IgG

Question 20

you have a calf 40 kg weight. how much colostrum in L is required if your colostrum contains 50 g/L IgG?

Answer 20

plasma volume is 9% of blood, minimum plasma concentration is 10g/L, apparent efficiency of absorption is 35%.
Plasma volume = 40 kg x 0.09 = 3.6 L
Required IgG = 3.6 L x 10 g/L / 0.35 = 103 g
Required amount to feed = 103 g / 50g/L = 2.1 L
(note that the max you could give a Holstein calf at a single feeding after birth is 3.8L)

Question 21

two methods to measure colostrum quality?

Answer 21

colostrometer (density) or optical refractometer

Question 22

what is the minimum IgG level of colostrum

Answer 22

50 mg/mL IgG

Question 23

calves are born with low energy reserves. what two immediate sources of energy are needed to maintain body temperature?

Answer 23

fat and lactose

Question 24

what has the higher kcal/g, colostrum or milk

Answer 24

colostrum (1.16 kcal/g vs 0.69 kcal/g)

Question 25

increasing the quantity of colostrum fed during the first 12h after birth is associated with: increased or decreased mortality

Answer 25

decreased mortality

Question 26

if a cow's colostrum is not good, two options to ensure adequate colostrum are

Answer 26

colostrum banks (store frozen 1 year, reheat in 50 degrees C water bath) or colostrum substitutes (not as good, but there are colostrum replacers, from cows at selected herds, cheese whey, bovine serum)

Question 27

a young calf is functionally a

Answer 27

non-ruminant

Question 28

after receiving ______ and ______ for first few days of life, calves are fed either ______ or ________ until weaning (types of milk)

Answer 28

colostrum and transition milk; milk or milk replacer

Question 29

nutritional requirements for calves are based on these 4 things

Answer 29

weight, growth, environment (temp and humidity) health (moderate infections increase energy need by 150-200%)

Question 30

what are 3 disadvantages of feeding 'hospital' milk to values

Answer 30

milk not suitable for shipping, poor quality (mastitis), antibiotic residue (these can inhibit healthy bacteria development)

Question 31

what is the risk of feeding raw milk to calves? what can producers do to combat this risk?

Answer 31

diseases eg. Johne's, BVDV, Salmonella. can pasteurize to reduce risk

Question 32

____ vary in composition and quality; they consist of animal fats (or other fats), whey, vitamins, minerals, AA, RBC protein and plasma protein, blended with an emulsifier, reconstituted with water to achieve 12% DM; fed at 1% body weight on DM basis, about 10% of BW

Answer 32

milk replacer

Question 33

milk replacers can be classified as

Answer 33

all-milk protein or alternate protein

Question 34

which contains the most ME: whole milk, milk replacer, or starter feed

Answer 34

whole milk contains the most. (starter feed the least)

Question 35

when are B-complex vitamins necessary in calf diets

Answer 35

when giving milk-replacer diets, until rumen fermentation is active

Question 36

list vitamins and minerals dairy calves require

Answer 36

vitamins A, D, E; minerals Ca, P, Se, Zn, Cu, K, I, S, Co, Mg, Na, Cl, Fe, Mn

Question 37

why do dairy cows need free access to water

Answer 37

water is needed for growth and consumption of dry feed; free access maximized starter intakes

Question 38

when does the rumen start to develop? when is it fully developed

Answer 38

when calf eats dry feed. by 6-8 weeks

Question 39

when is weaning? what is the weight goal at weaning time?

Answer 39

4-8 weeks and the goal is to double the birth weight

Question 40

tell me about calf starter

Answer 40

should contain 20-22% CP, high quality protein is needed, soybean meal is a common protein choice, often coccidiostat added, to improve intake and palatability use high quality ingredients, textured grains, added flavour, intact pellets; offer at first week (probably won't eat, but encourages them to eat it), continue giving until consuming 2 kg/day

Question 41

what promotes development of rumen mucosa and papillae

Answer 41

propionate and butyrate (concentrate is better for promoting development than hay, has more VFAs)

Question 42

what is a calf given in an accelerated calf feeding program?

Answer 42

milk replacer with higher protein concentration, fed about twice as much milk replacer per day

Question 43

give an advantage and a disadvantage of accelerated calf feeding program

Answer 43

high growth rates before weaning and reach breeding size earlier, but higher cost of production

Question 44

order the ADG from highest to lowest: calf fed with 10% whole milk (by BW), 10% milk replacer, 18% whole milk, 18% milk replacer

Answer 44

18% whole milk, 18% milk replacer, 10% whole milk, 10% milk replacer (ie. higher volume is better and whole milk is better)

Question 45

***why do calves need extra energy during cold weather***

Answer 45

***satisfy increase in maintenance energy requirements*** (limited body reserves and insulation at birth)

Question 46

what is the objective of feeding heifers from weaning to breeding

Answer 46

feed heifers to attain a pre-selected or target weight at a given age to achieve optimum first lactation performance while controlling cost or rearing replacements

Question 47

what are 2 negative effects of excess energy intake on heifers

Answer 47

negative effect on mammary parenchyma (mammary development) and reduced first lactation milk production

Question 48

after weaning, heifers will continue eating starter ration and should be introduced _________

Answer 48

high quality hay

Question 49

what can be introduced to heifers to replace starter when calves are 4 months of age, eating 2 kg starter daily

Answer 49

grower ration (contains 16-18% CP and monensin)

Question 50

what is given to heifers at age 6 months

Answer 50

silage-based total mixed ration (TMR)

Question 51

order the following diet types given to heifers between weaning and breeding: silage-based TMR, starter, grower, hay, liquid diet (based on the age they are first given, note there are overlaps)

Answer 51

liquid diet, starter, hay, grower, silage-based TMR

Question 52

what is mature shrunk body weight (MSBW)

Answer 52

weight of a cow after she delivers her third calf, following an overnight fast without feed or water

Question 53

***give target body weights: for first bred target BW, for first post-calving target BW?*** (bonus, give the second and third post-calving target BWs)

Answer 53

55% mean shrunk body weight (MSBW), 82% MSBW. (bonus: 92% MSBW, 100% MSBW)

Question 54

your target MSBW is 700 kg. what is your target weight at first breeding? what is your target weight after third calving?

Answer 54

385 kg (target is 55% of MSBW). 700 kg (100% MSBW)

Question 55

the phenotypic and genetic trends for stature in Holstein calves have been ______ over the last several decades

Answer 55

increasing

Question 56

during the first two thirds of pregnancy, nutrient requirements of Holstein heifers are needed for ________ and ________, so are overall ___ compared to last third of pregnancy

Answer 56

maintenance and continued growth, overall lower

Question 57

during last rimester of pregnancy, nutrient requirements increase significantly due to rapid growth of _____ and ______

Answer 57

fetus and associated tissues