Investing in sustainable calf milk replacer (CMR) quality from Volac Milk Replacers during those important eight weeks of early life certainly reaps dividends.

Heifer calves reared on a concentrated whey protein-based Volac CMR are younger at first calving (AFC) and more fertile than those receiving lower-quality milk protein in early life.

Significantly, this younger AFC benefit alone is worth more than €3,800 to a 200-cow herd with an average replacement rate.

“Dairy heifers at AFBI Hillsborough in Northern Ireland fed different milk protein-based diets as pre-weaned calves in 2018/19 have been monitored from birth up until their third calving,” reports Volac R&D manager Dr Jessica Cooke.

“The study involved 80 Holstein Friesian calves fed four different milk replacers from birth until 56 days of age.

"The trial highlighted that well-formulated, high-quality milk replacers with either skim milk powder (at a high inclusion level) or concentrated whey protein as the major source of dairy protein both deliver comparable animal performance.

“This work clearly showed that the presence of skim – and therefore the clotting effect of casein – is not the fundamental element within a calf milk formula influencing optimum calf growth.

"There was no significant difference between the calf growth or health from the different milk replacer formulations. If the important milk components are processed correctly, both skim and whey proteins will be highly digestible by the high milk fed pre-weaned calf and will deliver good performance.”

Dr Cooke stressed that good nutrition and calf performance is linked to more than just the type of dairy protein included in the finished milk formula.

“Important differences in amino acid and fatty acid profiles, amount of lactose, vitamins, minerals and trace elements, processing conditions and overall digestibility also all contribute to calf performance,” she says.

Later life pay-off

What’s more, the data confirmed that high-quality pre-weaned calf nutrition favourably influences better lifetime productivity.

“What calves are fed pre-weaning certainly makes a difference, as these heifers join the milking herd,” Dr Cooke says.

“Although high-quality, skim-based milk replacer-fed calves and those fed a high-quality, concentrated whey protein-based (CWP) pre-weaning diet will perform similarly in later life, some performance differences start to emerge when you compare calves fed CWP with those fed a lower quality, simple whey powder-based (WP) milk replacer (see Table 1).

“While the CWP-fed calves were only five days younger than their counterparts at first breeding, there were some fertility differences.

"For example, the CWP-fed group only required 1.4 services per heifer, while the WP-fed group required two services per heifer. First service conception rate was better too in the CWP-fed group (60%) versus 50% in the WP-fed group.”

However, Dr Cooke says that a particularly important performance difference starts to emerge when you compare the AFC data.

“On average, the CWP-fed calves calved first at 729 days of age, whereas the WP-fed animals calved down at 751 days – 22 days later. What’s more, 80% of the CWP-fed heifers had calved down by 24 months or age, as opposed to only 33% of the WP-fed heifers.

“With AHDB figures suggesting each day delay beyond 24 months AFC costs you €3.34, this performance difference alone is worth €73.41 per heifer. Or, to put it another way, a €3,800-plus cost to the dairy farm business every year for a 200-cow herd with a 25% annual replacement rate.”

Dr Cooke says that this research confirms that high-quality early life nutrition pays dividends and urged all calf rearers in Ireland to be far more discerning over CMR choice for rearing their milking herd replacements.

“The key is to evaluate value for money carefully when purchasing a CMR. Look for a proven track record of performance and recognise that a precision-formulated product based on concentrated whey protein (eg Volac’s Imunopro®) will provide everything the modern, high milk fed calf needs in early life – and improved lifetime performance,” she concludes.

Volac Milk Replacers has built its reputation in sustainable dairy calf nutrition. Pioneers in the manufacture of whey proteins and important derivatives from fresh whey, Volac Milk Replacers unlocks the power of this valuable nutritional by-product of cheese manufacture from local cows’ milk to improve the performance of dairy calves.

Table 1: Not all whey is the same

Calves fed milk replacer based on CWP (e.g. Imunopro®) were younger at first calving compared with those fed milk replacer with WP as the primary protein.


1. Richert SH, Morr CV & Cooney CM (1974). Effect of heat and other factors upon foaming properties of whey protein concentrates. Journal of Food Science 39.

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