Feeding young ruminants

Question 1

Describe the differences between the GIT of ruminating cattle and non-ruminating calves

Answer 1

Ruminating cattle:
- solid food source (concentrates and forage)
- 70-80% rumen size
- Numerous absorptive papillae
- pH = 6.2 - 7
- anaerobic microbiome for bacterial growth

Non-ruminating calf:
- liquid food source (milk)
- 25-30% rumen size
- no absorptive ability due to lack of developed papillae
- pH = 5-5.3
- sterile microbiome

Question 2

What is needed to help rumen development?

Answer 2

Inoculation and establishment of anaerobic ruminal microbial ecosystem
Initiation of starter feed consumption
Fermentation processes and absorption mechanisms

Question 3

What stimulates the growth of papillae in the rumen?

Answer 3

Presence of VFAs

Question 4

What is paraketosis?

Answer 4

Excessive development of papillae

Question 5

What is the effect of low rumen pH?

Answer 5

Undesired shift in microflora
Inefficient digestion
Decrease in rumen motility
increased keratinisation
Weaning = common time for low rumen pH

Question 6

Describe the development of the rumen microbiome

Answer 6

Sterile in newborn calf
Gain bacteria from environment and colostrum/milk
Starch (concentrates) => increase in gram -ve bacteria
Fibre (forage) => increase in gram +ve bacteria

Question 7

Describe skimmed milk replacer

Answer 7

Contains major milk proteins
Forms a clot (stays in abomasum for longer => feel full for longer)
Expensive

Question 8

Describe whey milk replacer

Answer 8

Made of mostly lactose
no functional abomasal clot

Question 9

Describe plant-based milk replacer

Answer 9

Contains non-milk based proteins
Not always easily digested as rumen not developed

Question 10

What are the aims of feeding solids to calves?

Answer 10

Stimulate microbial population
Stimulate rumen papillae formation
Development of rumination
Increase rumen capacity
Provide energy
Impact behaviour

Question 11

What is the aim of concentrate feeding in calves?

Answer 11

Provide VFAs from starch:
- microbial fermentation
- rumen epithelial development
- provide energy

Question 12

Describe how to concentrate feed calves

Answer 12

small amoutn Offered from day 3 after milk
Consumption starts at 2 weeks
Energy source at 3 weeks
Rumen functioning at 10-12 weeks
Calves housed together => learned behaviour

Question 13

What are the aims of forage feeding calves?

Answer 13

High fibre and lignin:
- development of ruminal muscular layers
- mitigate low rumen pH
- establishment of microflora prior to weaning
- chopped to 2” long - improves intake of concentrate

Introduced from day 3
should be available by 2 weeks

Question 14

Why is early water consumption important for calves?

Answer 14

rumen development
improved grain retention
better starter intake
provision of some GI bacteria

Question 15

When are beef calves usually weaned?

Answer 15

6-8months

Question 16

When should creep feed by introduced to beef calves?

Answer 16

6-10 wks prior to weaning:
- reduces stress
- minimise drop in performance
- reduce pneumonia risk

Question 17

What should dairy calves be weaned

Answer 17

commonly weaned at 8 wks
Minimum = 6wks

Question 18

What is step-down weaning in dairy calf weaning?

Answer 18

Encourages starter intake during pre-weaning period
25-50% reduction in milk 10-14 days prior to weaning
2nd reduction 5-7 days pre-weaning
Increased solid feed consumption =>
- rumen development
- higher starter intake
- high BW gain after weaning

Question 19

What are the signs of problems with the transition at weaning?

Answer 19

reduced growth rates
GI issues e.g., bloat or diarrhoea (Scours)
increased levels of disease e.g., pneumonia

Question 20

Describe an appropriate diet for dairy calves 0-8wks old

Answer 20

Whole milk/milk replacer
Ad lib concentrate and forage

Question 21

Describe a diet for dairy calves 8-10 wks old

Answer 21

Eating >1-2kg concentrate
Gradual decrease of milk
Increase amount of concentration
ad lib forage

Question 22

describe a diet for a dairy calf from 10 wks onwards

Answer 22

Concentrate
forage
moving to higher percentage of a higher energy dense forage

Question 23

Describe the diet for beef calves at birth

Answer 23

milk from dam
ad lib access to dam

Question 24

Describe the diet for beef calves on the run up to weaning

Answer 24

Creep feed
Access to forage (grass/silage)

Question 25

Describe the diet for a beef calf that has been weaned

Answer 25

Growers ration

Question 26

Describe the diet for a lamb at birth

Answer 26

Milk from ewe/milk replacer
ad lib access to creep feed

Question 27

Describe the diet for lambs at weaning

Answer 27

~60-90 days
Creep feed/grass

Question 28

Describe the diet for a growing lamb after weaning

Answer 28

usually forage based
can supplement

Question 29

Why should silage feeding be avoided in growing ruminants?

Answer 29

rumen cannto utilize silage properly until it is fully functional

Question 30

What is the target growth for calves

Answer 30

0.8kg per day
55-60% mature BW at 13-15 mnths

Question 31

What is the target growth for lambs?

Answer 31

250g per day (min)
Wean at ~12-14 weeks
60% mature BW at mating at 18-20 months