Milk replacer

What is milk replacer?

Milk replacer, or CMR for short, replaces whole milk in calf rearing. It comes as a powder and is mixed with warm water. Many farms use it because the whole milk can then be sold and the replacer has a consistent composition. Others feed whole milk and enrich it with a supplement.

Milk replacer comes after colostrum. In the first days of life the calf gets colostrum and then transition milk. Only then does it switch to milk replacer or whole milk.

What is milk replacer made of?

• Protein from milk, mainly skimmed milk powder and whey powder. Some products also contain plant protein, for example from wheat or soya.
• Fat, usually vegetable fats such as coconut or palm fat, for energy.
• Lactose from the whey.
• Vitamins, trace elements and sometimes additives for gut health.

The label lists crude protein and crude fat. For young calves, replacers with a high milk content are easier to digest, because the calf uses plant protein less well in the first weeks.

Mixing it correctly

Stick to the mixing ratio on the pack. Milk replacer that is too thin supplies too little energy, while milk replacer that is too concentrated puts strain on the gut. For intensive feeding, milk replacer is often mixed at about 15 percent dry matter, so fairly concentrated. Weigh the powder instead of measuring it by eye.

The feeding temperature should be between 35 and 40 °C. Milk that is too cold is a common non-infectious cause of diarrhoea, as is a wrong mixing ratio or a sudden change of product.

How much milk replacer?

Calves used to be fed restricted amounts so that they would start eating concentrates early. We now know that intensive milk feeding increases later milk yield. In the first three weeks calves can drink ad libitum, often 10 to 14 litres a day. After that the amount is reduced slowly while intake of calf starter and hay goes up. The aim is at least 800 grams of daily gain before weaning. Read more in Metabolic programming of calves.

Hygiene and feeding equipment

Milk is a good breeding ground for bacteria. Clean buckets, teats and automatic calf feeders after every feed, first with an alkaline cleaner to remove fat and protein, and regularly with an acid cleaner to remove limescale. Damaged teats with too large a hole make the calf drink too fast, so milk runs into the rumen instead of the abomasum. Teat buckets or automatic feeders with a teat are better than an open bucket, because the suckling reflex closes the oesophageal groove.

Keep feeding milk during diarrhoea

Calves with diarrhoea should keep getting their milk or milk replacer, otherwise they run short of energy. Electrolyte drinks are given between milk feeds, not instead of the milk. Read more in Calf diarrhoea? 5 steps to stay ahead of leaky gut.

Changing products and weaning

Do not change product abruptly. Mix the old and new product over a few days. For weaning, the amount of milk is reduced step by step over two to three weeks. The calf should then eat at least 1.5 to 2 kg of calf starter a day, otherwise growth drops.

Frequently asked questions

All terms in the glossary