The benefits of maximising growth potential in youngstock are well documented, but there are a range of methods of how best to wean calves to improve rumen development when calves are born with a non-functional rumen.

According to Alan Smith, business manager for Volac in Scotland, weaning over a three-week period is encourages increased starter feed intake, and rumen development while also improving the calf's ability to digest nutrients after weaning.

“The rumen must be sufficiently developed at weaning so that it can digest and utilise solid feed, which supplies the nutrients previously supplied by milk,” explains Volac business manager for Scotland, Alan Smith.

“Rumen development is driven by the fermentation of calf starter by the rumen bacteria, which is why this solid feed must be available in small amounts early in life, be correctly formulated for the young calf and always offered clean, fresh and palatable.”

He added that calves fed more milk will not be driven by hunger to eat starter feed to support weaning which means high milk fed dairy calves need to be encouraged to eat solid feed by implementing management strategies that balance the intake of nutrients from both milk and starter feed.

Therefore, Mr Smith advised introducing a alf starter should be introduced from days three to five even though calves don’t typically begin consuming measurable amounts of solid feed until they are around two weeks of age.

“By five weeks of age calves should be eating 0.5kg of starter feed per day. Calves should be eating 0.7-1kg per day by six to seven weeks of age and a minimum of 1.5kg per day at weaning.”

Offering forage alongside starter feed is also important for healthy rumen development.

“Feeding forage helps stabilise the rumen pH, stimulates its muscular layer and maintains the integrity and health of its wall. What’s more, providing chopped barley straw – separately from starter feed during the high milk feeding period – has been shown to stimulate starter intake, improve calf weight gain and even boost forage intake after weaning.”

Volac advises gradually reducing the amount of milk offered to calves, over a three-week period between days 35 and 56 (see table 1). This encourages starter intake, helps rumen development and improves the ability of the calf to digest nutrients after weaning.

“For the high milk fed calf we now recommend a three-week weaning period between days 35 and 56 where milk replacer is fed at ≤ 750g milk solids per day to ensure calves eat enough starter to allow for sufficient rumen development,” he says.

Calves that are fed more milk over the first five weeks of life will be bigger and more vigorous. These calves will subsequently eat more starter when milk is gradually reduced from day 35 to 56. What's more, calves fed more milk, coupled with good starter intakes, will be more likely to achieve their early growth targets and lifetime milk production potential.

Table 1.

Recommended milk feeding plan with a three-week weaning period (for calves fed twice daily).

Stepping down period shaded in grey.

Week Age (days) Twice daily feeding rates (litres)*


1 0-3 Feed colostrum

4-7 2.5 2.5

2-5 8-35 3 3

6-7 36-49 2.5 2.5

8 50-56 2.5 0

9 57+ 0 0

*Volac milk formula mixed at either 12.5% or 15%

The reduction in milk solids per day will be specific to each individual dairy farm. For detailed advice on stepping down milk powder feeding levels on your unit, please speak to your local Volac business manager.

Social housing

Pairing or grouping calves from one week of age will also improve starter intake and increase weight gain, compared to calves which are grouped together later during the milk feeding period as a result of peer stimulation.

“We recommend that calves be individually housed for the first week of life before being moved into a pair or group. However, young calves should always be housed in a separate calf unit to reduce the spread of disease from older cattle to more susceptible younger animals,” Alan Smith says.

In a box:


1. Starter feed must be clean, fresh and palatable (offer small amounts daily).

2. Offer starter feed from 3-5 days of age

3. Always use a high-quality starter feed that has been formulated for calves (crude protein content of at least 18%).

4. Calves must be eating at least 1.5kg per day of starter feed at weaning.

5. Provide clean, fresh, ad lib water from day one.

6. Offer chopped forage separately from starter feed (e.g. barley straw; 3-4cm chop length) from one week of age.

7. Pair or group house calves from one week of age.

8. Wean calves at 56 days of age (by 63 days of age at the latest).

9. Wean gradually over a three-week period (feeding ≤ 750g milk solids per day from day 35 to 56).