Achieving calf growth rates

Find out how to feed a growing calf’s energy requirements and reach target growth rates.

For calves under three weeks old, energy requirements should be met through milk feeding. For those over three weeks, energy requirements can be met through a combination of milk and concentrate feeding.

The amount of whole milk or milk replacer to feed will depend on body weight, desired growth rate, environmental temperature and nutritional composition.

To determine whether a growing calf is receiving enough energy from milk replacer or whole milk to meet its growth rate targets, calculate its energy requirements. The energy content of whole milk (3.28% protein and 4.00% fat) on a dry-matter basis is 22.71 MJ/kg. Using information on the label, you can estimate the energy content provided by a milk-replacer product.

The calf’s total feed requirements depend on its age, target growth rate and environmental conditions.

Calculating the energy content of milk replacer

Use the Calf milk replacer energy calculator to work out the energy supplied by the amount of milk replacer fed to the calf.

Calculating calf energy requirements when fed milk or milk replacer

The ME requirements of calves that are fed milk or milk replacer at different liveweights, with various daily gains, are shown in the table below.

These energy requirements assume that the calf’s environment is 15°C–20°C. For each 5°C drop below 15°C, calves under three weeks old should be fed an extra 50 g/day of milk replacer, or 0.33 litres/day of whole milk, to provide them with the energy they will need to stay warm and maintain growth rates.

If you would like to order a hard copy of the Calf management guide, please contact publications@ahdb.org.uk or call 0247 799 0069.