Time4Calving: Our Guide To Calf Milk Replacers

calf milk replacer

To reach the optimal serving weight by 13 – 14 months old, with the aim to calve down at 24 months, heifer calves must be growing at 0.85kg/day from birth to first service.
Our expert calf and youngstock team are able to offer on-farm advice on feeds and nutrition to help dairy youngstock reach these targets. However, they have also compiled a few top tips on what to consider when it comes to feeding milk replacers for your own reference:

Quantity

Calves should be fed 15–20% of their body weight each day in whole milk or a suitable milk replacer to reach the targeted 0.85kg/day growth rate.

During cold weather, the volume of milk replacer fed should be increased to reflect the fact that calves will be using more energy to keep warm.

If temperatures fall below 200C, for every 10ºC drop, an extra 100g milk powder/day should be fed to a 50kg calf (0-3 weeks of age). So at 0ºC, feed an extra 200g per day. This should be achieved through increasing the volume of milk fed, rather than the concentration. Increasing the concentration will affect osmolality levels and can increase the risk of nutritional scour.

For calves older than three weeks, if temperatures fall below 100C, feed an extra 100g milk powder/day for every 10ºC drop. So at 0ºC, feed an extra 100g per day. This should also be achieved through increasing the volume of milk fed, rather than the concentration.

Schedule

It is important to keep calves on the same milk replacer until weaning as this will avoid upset to their digestive systems, which could result in nutritional scours.

fed at consistent times every day to help the abomasum break down the milk efficiently and prevent digestive issues, such as bloat.

Temperature

Milk replacer should be fed at a temperature of 37 – 39 ºC, as this is within the range of a calf’s body temperature.  This is particularly important during cold weather conditions to avoid lowering the calf’s internal body temperature. For tips on how to correctly mix milk replacer, watch our handy guide below:

Nutritional content

Dairy heifers will require a powder containing at least 22% protein to meet their nutritional requirements. However, some higher protein products, if they are of good quality, will encourage more stature and lean muscle development.

Most milk replacers contain a mixture of dairy and vegetable protein and the quality of the protein and how it has been processed is important. Look for hydrolysed wheat protein as the vegetable protein as it will provide a digestible alternative to dairy protein.

Pea protein, soya protein, wheat protein and wheat flour are typically harder for youngstock to digest and are therefore less available to the young calf. Soya protein concentrate is sometimes used in more economic milk replacers, but its digestibility is much lower than that of hydrolysed wheat.

Additionally, aim to feed a replacer with no less than 20% fat. Calves require energy to keep warm, to fight off infection, to move, and to grow. Calves are not at risk of becoming over fat during the milk feeding period, so the higher the fat content, the better. Fat also provides energy for protein utilisation and therefore encourages higher rates of growth.

Whey or skim?

Whey and skim milk replacers are digested differently by calves. Once skim milk reaches the abomasum, it produces an energy dense casein (an insoluble milk protein) clot that takes between eight to twelve hours to be fully digested. For this reason, calves on a skim-based milk replacer will appear fuller for longer than calves fed with a whey-based milk replacer.

Whey powders contain the whey fraction (a soluble milk protein) of milk which does not need to be clotted to be broken down, so goes straight to the small intestine for digestion. Whey-based milk replacers are therefore digested much faster, typically within two to three hours.

There are no advantages of choosing one type of milk replacer over the other, so long as the quality and digestibility of the raw materials is high. Make sure you speak to your local calf and youngstock specialist to find a replacer to best suit your system.

Provide straw, starter feed and water

Starter feed, straw and water should be provided from birth.

Although they won’t eat large amounts in the first few weeks, allowing access to starter feed will help with rumen development. At birth, a calf’s digestive system has the same four compartments to an adult cow, but only one compartment is fully functioning – the abomasum.

The rumen is under-developed at this stage, but this is the compartment that will become the powerhouse of the calf after weaning. It is therefore essential to encourage rumen development as quickly as possible whilst the calves are on milk.

We do this by providing starter feed rich in starch, which will produce important volatile fatty acids that stimulate growth of the rumen wall, and papillae development on the internal lining.

Equipment hygiene

Feeding equipment should be cleaned and disinfected after each feed to reduce the incidence of disease. If you want to know more about on-farm biosecurity and hygiene, read our calf management blog here.