Lecture 12- Calf development and nutrition before weaning

Question 1

When are calves separated from their mothers?

Answer 1

So dairy calves are physically separated from their dams within hours (or a few days) after birth, but we call them unweaned until they stop drinking milk !

Question 2

What was the study into the abomasum in calves?

Answer 2

• put a fistula in to study the milk coagulation properties
• put in milk replacer
• even after 5 mins the protein is aggregating, after 10mins, the 25 or 35 mins get cottage cheese
• that is how cheese is made
• if cow’s milk= at 5 mins have the cheese and at 60 mins complete cheese so much better (actual cottage cheese)

Question 3

How is pH in the calf’s abomasum affected by a milk replacer and milk?

Answer 3

• similar
• when you put the feed in the pH increases and then acid comes in the pH goes down
• the cheese production is different but it is not pH

Question 4

What is newborn-weaning?

Answer 4

Newborn-weaning:

• Birth till weaning: Develops from being functionally monogastric to become a ruminant

Question 5

What is weaning calf?

Answer 5

Weaning (we decide weaning age!)
• after 7-8 weeks – conventional herds
• after 13 weeks – organic herds
• Beef calves ??
• Natural weaning age ??

Question 6

What is the most important period in young calf’s life?

Answer 6

The most important period in young calf’s life
• First 24 h – colostrum of good quality within 6 h
• First 2-3 weeks

Question 7

What is the challenge with unweaned calfs?

Answer 7

What we have:
• Newborn vulnerable calf that needs expensive and laborious feeding, attention and work
• Very small nutrient depots in the body
• Immature digestive system and-function
• No forestomach capacity
• Immature immune defence and microflora in GIT
• Infection pressure–dirty surroundings
• Busy farmer who has to earn money

-What we want:
• Robust and healthy calf
• Resistance towards infection pressure
• Can cope with small imbalances in feeding
• Easy and cheap feeding and feedstuffs (solid feed, concentrates, roughages)
• Long term goal: good beef calf / productive cow

Question 8

What is the challenge with unweaned calfs?

Answer 8

Conflict between ”Have” and ”Want”
- Too little and too poor colostrum = more vulnerable to infections
- Restricted milk feeding
=solid feeds
- reticulo-rumen development
- energy-, nutrient uptake, daily gain
- Too little and too poor roughage and too much starch-rich concentrate
- rumen acidosis / rumen epithelial damage / low growth rate ???

Question 9

How much milk will a calf drink if it has free access?

Answer 9

• if you want to maximise the output of the calf then feed it more milk
• if fed from bucket or sucking
• in first 20 days will be below ten liters then after that will drink more

Question 10

What is the relationship between the consumption of milk and concentrate?

Answer 10

-if not enough milk will eat more concentrate

Question 11

How is milk intake level connected to uptake of solid feed after weaning?

Answer 11

• Uptake of solid feed AFTER weaning – little effect of previous milk intake level
• if high milk then will eat less concentrate for a week but then will eat enough
• so effect for about a week

Question 12

What is the difference in stomach compartments in a calf and an adult cow?

Answer 12

• calf has abomasum dominant stomach
• the reticulum etc. forms later
• via the esophageal groove the feed enters the abomasum, instead of going anywhere else, if the groove is not closing the milk goes to the rumen= rotten soup then and can make them sick

Question 13

How does the development of forestomachs and microbial digestion?

Answer 13

-Solid, fermentable feed stuffs are required
• Anaerobic conditions and buffering are essential
• Milk spill from esophageal groove risk of rumen decomposition (rotten)
Physical fill will develop size and smooth muscles in rumen wall
SCFA (Acetate, propionate and butyric acid) produced by the bacteria will stimulate epithelium and papillae
• butyrate > propionate > acetate Good quality roughage is important
Microflora is usually developed without help of additives

Question 14

What are the solid feeds= concentrates and roughages for the cows?

Answer 14

-No capacity at time of birth (rumen very little)
• no microflora, little volume and low saliva production
• salivay-bicarbonate concentation first optimal at 6-7 wks
High digestibility and ‘calf-tasty’ will increase uptake
• SCFA – develop papillae and provide energy
• Even small amounts (and not only starch) lead to a risk of acidotic rumen conditions in the first wks, if no roughage is supplied
Structure / roughage is important
• Roughage – develops volume/size and stabilizes rumen environment
• Roughage needs to be highly digestible – grass-clover hay, lightly-fermented silage, sugar-rich, leaves not stems

Question 15

What is the case with single or pairwise housing of calfs?

Answer 15

-need to touch each other so having at least two in one

Question 16

What was the ambition with developing new nutrient diet for calfs?

Answer 16

• Background- High mortality among calves
• Question and challenge current dogma–inDK and USA
• Develop a rumen-fistulated calf for use in intensive experiments in week 1 to 10 of life
• Try extreme and alternative feedings
• And finally develop a ‘New Feeding Concept’
• Feeding should allow for high growth rates
• …. Our experiences …. To be shared ….
-so don’t need the palates at all

Question 17

What was the effect of the new feeding concept on cows?

Answer 17

Ad libitum milk to heifer calves resulted in higher milk yield as cows