Bovine Nutrition

Question 1

What is ERDP? Give an example

Answer 1

Effective rumen-degrading protein eg urea

Question 2

What is FME? Give an example

Answer 2

Fermentable metabolisable energy ie starches and sugars

Question 3

What is RUDP?

Answer 3

Undegradable rumen protein
Digested in abomasum and small intestine
eg soya
High quality, expensive

Question 4

How much protein does a dairy cow require?

Answer 4

16% if yield < 8000L

18% if yield > 8000L

Question 5

How much protein is in grass silage?

Answer 5

12-18%

Question 6

What is ME?

Answer 6

Metabolisable energy

Energy available to animal for maintenance, growth, lactation and pregnancy

Question 7

What is the capacity of the rumen?

Answer 7

200L +

Question 8

What are carbohydrates fermented to?

Answer 8

Volatile fatty acids (acetate, butyrate, propionate)
CO2
Methane

Question 9

What happens to VFAs in the rumen?

Answer 9

Absorbed across rumen wall
Enter Krebbs cyce
Glucose synthesis (from propionate)

Question 10

How much does a ruminant eat?

Answer 10

2-2.5% BW if doing nothing
If lactating: 3% BW if producing 30L/day, 4% BW if producing 50L/day
If heavily pregnant, eats less as foetus occupies space in abdomen

Question 11

Give some factors that influence DMI

Answer 11

Body weight and fatness (fat suppresses appetite)
Milk yield
Stage of production cycle
Type of food (digestibility)
Palatability
Access to feed
Availability (TMR vs parlour feed etc)
Social factors eg bullying
Stress/pain eg lameness
Rumen health

Question 12

When do cows ruminate best?

Answer 12

When lying down

Question 13

How much energy does a cow require for maintenance?

Answer 13

65-70MJ

+ 5MJ/litre of milk

Question 14

What are ghrelins?

Answer 14

Hormones involved in appetite

Question 15

When is milk yield highest?

Answer 15

8 weeks after calving

Question 16

What DMI should you aim for at peak milk yield?

Answer 16

4% (appetite)

Question 17

What M/D values should lactating, dry and cows at pasture be fed?

Answer 17

Lactating cows: 11.5-12.3 MJ ME/kg DM
Dry cows: 8-8.5 MJ ME/kg DM
Cows at pasture: no more than 14 MJ ME/kg DM

Question 18

What are the DM and M/D values for clamp grass silage?

Answer 18

DM: 20-35%

M/D: 10-12 MJ ME/Kg DM

Question 19

What are the DM and M/D values for maize silage?

Answer 19

DM: 30-35%
M/D: 11-11.5 MJ ME/Kg DM
(High starch so fast fermenting, low protein, poor fibre source)

Question 20

What are the DM and M/D values for big bale silage?

Answer 20

DM: 30-35%

M/D: 8.5-10.5 MJ ME/Kg DM

Question 21

What are the DM and M/D values for hay?

Answer 21

DM: 85%

M/D: 8-9 MJ ME/Kg DM

Question 22

What are the DM and M/D values for straw?

Answer 22

DM: 85%

M/D: 5.5-6.5 MJ ME/Kg DM

Question 23

What are the DM and M/D values for grass?

Answer 23

DM: 20% or less

M/D: 10-12.5 MJ ME/Kg DM

Question 24

What are the DM and M/D values for concentrates/cake?

Answer 24

DM: very dry!

M/D: 12.5 MJ ME/Kg as fed

Question 25

Where do cows get most of their vitamins from?

Answer 25

Rumen bacteria

Question 26

What are the management aims during the dry period?

Answer 26

Avoid getting fat
Rest period
Mammary regeneration
Rumen development (suitable bugs for post-calving diet, big and muscular, big healthy papillae for good absorption

Question 27

How long is the dry period?

Answer 27

60 days

Question 28

What happens to DMI during the dry period?

Answer 28

Decreases, therefore good to get cows eating as soon as they calve

Question 29

What kind of diet should you feed during the dry period?

Answer 29

Lasts 8 weeks:
5 weeks: Low energy/high fibre diet
3 weeks: ‘transition diet’
Should also pay attention to the 3 weeks after calving

Question 30

What DMI should a cow have in the early dry period?

Answer 30

10-14kg

Question 31

How much M/D energy should a cow be getting in the early dry period?
What kind of diet should this be?

Answer 31

7.5-8.5 MJ/day (low energy)

High fibre for rumen health

Question 32

Why should you not feed too much energy in early lactation?

Answer 32

Suppresses appetite

Predisposes to metabolic disease in lactation (‘fatty liver’, diabetes)

Question 33

How much energy does a cow need in a transition diet?

What about M/D value?

Answer 33

110-120 MJ/day

M/D: 9.5-10 MJ ME/Kg DM

Question 34

How much crude protein does a cow need in a transition diet?

Answer 34

13-15%

Question 35

Keeping many cows on a small patch of grass is a risk factor for what?

Answer 35

Strep uberis mastitis

Question 36

What should you feed in a transition diet?

Answer 36

Silage and straw and 2-2.5kg dry cow concentrate

Question 37

When should you move a dry cow to a calving pen?

Answer 37

Early 2nd stage of labour

Question 38

How much feed barrier space should a cow have?

Answer 38

At least 90cm/cow

Question 39

Is it better for a cow to be fat or thin before calving?

Why?

Answer 39

Thin
Fat cows lose more BCS in early lactation, and have smaller increases in milk yield
Fat cows before calving become thin cows after calving

Question 40

When does most metabolic disease occur?

Answer 40

In the first 10-12 weeks of lactation

Question 41

Give some problems that can occur in cows after calving

Answer 41

Ketosis
Milk fever (hypocalcaemia)
RFM/metritis/endometritis
Mastitis
Displaced abomasum
Fertility problems
Lameness

Question 42

What happens to DMI during gestation?

Answer 42

Decreases

Question 43

What DMI should you aim for in the dry period?

Answer 43

12-14kg

Question 44

What is a ‘far off diet’?

Answer 44

Early dry period diet

Silage plus straw

Question 45

When is a cow’s peak DMI?

Answer 45

4-10 weeks post-calving

Question 46

What is the ‘keenan diet’?

Answer 46

One diet for the whole dry period
Low energy (95-100 MJ/day, 12-13 kg DMI, M/D 8-8.5)
Include chopped straw