Calf Rearing Series 2026
In this second instalment of the series, we look at how to ensure you are choosing a quality milk replacement.
Supplying pre-weaned calves with high quality nutrition is an essential part of the ‘optimal environment’ required to maximise dairy youngstock performance levels in early life.
But Dr. Jessica Cooke from Feed For Growth (Volac Milk Replacers) says you have to look behind the calf milk replacer bag label.
According to Dr. Cooke, always opting for high quality pre-weaning calf nutrition using a proven, precision-formulated milk replacer product really pays off.
She explained: “We know that heifers with good growth rates, together with good fertility - as well as being bred at the right time - are those most likely to calf for the first time at 24 months-of-age with 85-90% of their mature body weight.
“It's the heifers that calve for the first time at 24 months-of-age with adequate body weight that we know have better fertility, produce more milk, have better udder health, and have the best survival.
"All of those traits drive lifetime daily yield – and it's the animals with the highest lifetime daily yields that are going to be the most profitable and bring with it an environmental benefit in terms of lowering the carbon footprint per litre of milk,” she said.
Dr. Cooke recommends feeding calves a milk replacer based on either concentrated whey protein, or one based on a high level of good quality skim.
“Research work at (Agri-Food and Biosciences Institute) AFBI Hillsborough highlighted that well formulated, high quality milk replacers with either skim milk powder (at above a 40% inclusion level) or concentrated whey protein as the major source of dairy protein both deliver comparable animal performance.
“Always be cautious about how whey protein is described on the label when comparing milk replacer – and always ask a merchant or manufacturer to explain the differences.
"If favouring a skim-based calf milk replacer, always opt for a high (>40%) skim content. And be wary of poor quality ingredients and fillers,” she stressed.
Not all whey is the same
Dr. Cooke explained that liquid whey from cheese production can be processed in a variety of ways, resulting in different types of whey, including whey powder, delactosed whey, and concentrated whey protein.
“The different types of whey differ in both protein and lactose content. Concentrated whey protein typically contains 35% protein but whey powder only contains 12.5-13% protein," she continued.
"Consequently, it’s important to realise that any whey powder in a finished milk formula will not contribute the same level of dairy protein to a calf compared with one based on concentrated whey protein, such as Feed For Growth’s Imunopro.”
Processing issues
She added that it is important to bear in mind too that the whey fraction of colostrum and whole milk contains valuable bioactive proteins (e.g., immunoglobulins and lactoferrin), which are not present in casein.
“These functional proteins are essential for calf health (supporting defence mechanisms) and influence the growth of the young animal," Dr. Cooke explained.
“However, care must be taken to minimise the protein denaturation of these valuable bioactive proteins during manufacture.
"Data shows that at processing temperatures of 85°C, over 60% of whey proteins were denatured within 30 minutes, whilst at 65°C only 15% of proteins were denatured.
“Fortunately, Feed For Growth’s modern low temperature ultrafiltration process ensures that a high proportion of the naturally occurring immunoglobulins found in liquid whey are retained in the company’s latest finished whey protein concentrate-based milk formulas,” she said.
In summary, this means that when processed under carefully controlled conditions, both skim and whey protein concentrate-based milk replacers can deliver excellent calf performance – and better lifetime performance potential.
But, on the other hand, poorly processed milk-derived protein (be it skim or whey) can have very poor digestibility and increase the risk of health issues.
“The key is to evaluate value for money carefully when purchasing a calf milk replacer," Dr. Cooke said.
"Look for a proven track record of performance and recognise that a precision-formulated product based on concentrated whey protein or a high proportion of skim will provide everything the modern, high milk-fed calf needs in early life - and improve lifetime performance."
For further information, get in touch with the Irish Feed For Growth team here.
