Cattle 1 calves and youngstock

Question 1

when are majority of calf deaths

Answer 1

at parturition

Question 2

Direct vs maternal selection for calving ease

Answer 2

Direct = selecting for offspring that were born easily
Maternal = selecting for how easily that animal will calve in future e.g large pelvis size

Question 3

What counts as a premature calf

Answer 3

One born before 270 days gestation

Question 4

WHat happens to IgG conc in colostrum in hours following birth

Answer 4

Decreases by 3% per hour

Question 5

How much colostrum should a calf be drinking in first 6 hours

Answer 5

10% body weight
= around 4L in a 40kg calf

Question 6

What serum IgG concentration does a calf need for adequate passive transfer

Answer 6

> 10g/L

Question 7

What does a colostrometer measure

Answer 7

Specific gravity

Question 8

What does a brix refractometer measure for colostrum

Answer 8

% solids
Minimum we want is 22% (equivalent to >50g/L)

Question 9

Colostrum management in bull calves

Answer 9

Natural sucking is enough; Ig concentration very high in colostrum much >100g/L

Question 10

What disease are we worried about being spread in harvested colostrum

Answer 10

Johne’s disease

Question 11

For colostrum supplementation what quality colostrum do we want

Answer 11

Very high
>150-200g/L

Question 12

Ways of assessing colostrum feeding in calves

Answer 12

1) zinc sulphate turbidity test: precipitation of IgG in serum and colorimetry
2) Total potein
3) GGT test: because present in colostrum and passes through like IgG

NB: must be done between 1-7 days; after this they make their own IgG

Question 13

What is the base level of total protein in a newborn calf (i.e no including colostrum)

Answer 13

45g/L

Question 14

Total protein level interpretation in a few days old calves

Answer 14

< 50g/L = poor
51-57 = fine
58-60 = good
61+ = excellent

remember base level is 45g/L

Question 15

Lower critical temperature for different age cows

Answer 15

Newborn: 15 degrees
1 month old: 5 degrees
Adult: -20 degrees

Question 16

How long can you keep calves in individual pens

Answer 16

Until 8 weeks old

Question 17

When must we ear tag calves

Answer 17

within 36 hours of birth

Question 18

Until what age can we elastrator to castrate a calf

Answer 18

7 days old

Question 19

Traditional feeding of dairy calves vs new

Answer 19

2 litres 2 times per day for 2 months
BUT this does leave them hungry

New idea: 6-8L per day BUT risk that this prevents rumen development

Question 20

Quality of milk replacer to feed dairy calves

Answer 20

22-25% crude protein from milk source, 20% highly digestible fat

Question 21

When do we wean dairy calves

Answer 21

When they can eat 1kg of starter ration
Around 6 weeks

When about double birth weight i.e >70kg

Question 22

What drives the development of the rumen

Answer 22

Volatile fatty acids produced by fermentation of starter carbohydrate ration

+ supply water (milk bypasses rumen)