Why it pays to feed high-quality milk replacer

Heifer calves reared on a concentrated whey protein-based calf milk replacer 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, according to Dr Cooke.

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. Dr Cooke explains: “This work clearly showed that the presence of skim 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 are 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

The data confirmed that high-quality pre-weaned calf nutrition favourably influences better lifetime productivity. “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.

“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 (60per cent) versus 50 per cent in the whey protein-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 per cent 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+ cost to the dairy farm business every year for a 200-cow herd with a 25 per cent annual replacement rate.” Dr Cooke says that this research confirms that high-quality early-life nutrition pays dividends.

“However, always be cautious about how whey protein is described on the label when comparing milk replacer. If favouring a skim-based calf milk replacer, always opt for a high (>40 per cent) skim content,” she stresses. 

“Bear in mind, too, that the different types of whey differ in both protein and lactose content. Concentrated whey protein typically contains 35 per cent protein, whereas whey powder only contains 12.5-13 per cent protein. Consequently, always look for a proven, precision-formulated calf milk replacer based on concentrated whey protein. This will provide everything the modern, high milk fed calf needs in early life – and improve lifetime performance.”