The cost of rearing calves this spring is set to increase sharply, as milk replacer costs increase by 20% compared to this time last year. A big increase in the costs of milk replacer ingredients is being blamed on the price increases.

To be fair to manufacturers, the main raw ingredients for milk replacers (dairy powders) have shot up in price over the last 12 to 18 months.

This is reflected in the increased price of milk at farm level compared to this time last year. The average cost per litre of milk replacer, based on the prices outlined in Table 1 on page 41, is now 33c/l, based on a 12.5% inclusion rate. This is up almost 20% on the same costs last year.

Dairy farmers can decide on whether to feed milk replacer or whole milk to calves this year. Which to choose will depend on the value of the milk that they could sell and the cost of the milk replacer.

With base milk price touching 40c/l including VAT, there is a significant opportunity cost with feeding whole milk.

However, this needs to be weighed up against the extra work and equipment needed to mix and prepare milk replacer.

Another factor is the quality of milk replacers relative to whole milk. This will vary from herd to herd, depending on milk constituents and the type of milk replacer used.


In most spring-calving herds, solids are lowest in the first few months of lactation.

To get an idea of the solids percentage in the milk, add up the fat, protein and lactose percentages in milk supplied last February and March.

A typical herd doing 3.4% protein and 4.2% fat in February and March is delivering 11.8% solids in whole milk, whereas most milk replacers are formulated to be fed at 12.5%. The rate of milk fed can be adjusted to account for the difference, but this will mean feeding more milk.

However, there will be differences in the quality of the proteins and fats in milk replacer versus whole milk, with whole milk generally much more digestible than some of the fats and proteins used in making milk replacers.

In terms of specification, protein levels are hugely important for growing animals like calves.

However, the source of that protein is probably as important as the level of protein itself. Vegetable-based proteins are less digestible than dairy-based protein such as whey and skim.

While many milk replacers will contain a blend of dairy and non-dairy proteins, we don’t really know the exact proportions of each.

The cost of milk replacer has increased in line with rising milk prices.\Donal O'Leary

Milk replacers with a high level of vegetable-derived proteins tend to have higher fibre contents.

Animal Health Ireland (AHI) says milk replacers with a fibre content greater than 0.15 indicate the inclusion of plant-based proteins.

Ideally, these milk replacers should not be fed to young calves who are not able to digest plant-based proteins.

They can be more suited to older calves who are better able to digest solid feeds.

The oil content in milk replacers replaces butterfat and according to AHI, is a good substitute for it. The ratio of protein to oil and the level of protein in the milk replacer is often used as a key selling point.

Generally, higher protein milk replacers will facilitate faster growth rates, but whether or not the extra cost is justified is farm specific.


When mixing milk replacer, calculate the total amount of feed you need. For example, if you are feeding 10 calves 2l of milk you need 20l of mixed milk in total.

If the feeding rate is 15% the calves need to get 300g of powder each at each feed, or 3kg of powder for the bunch.

Because milk powder will displace water, you should reduce the amount of water used by the quantity of powder.

So, instead of mixing 3kg of powder into 20l of water, you should mix 3kg of powder into 17l of water to make 20l of mixed milk.

When mixing, pour the correct amount of milk powder into half the desired amount of water and mix with a whisk or other mixing device. Then, add the rest of the water.

Never mix with boiling water, as this could corrupt the proteins. Only ever mix and feed with water at or below body temperature. Milk replacer can be successfully fed cold.