As the colder winter weather starts to bite, heifer calf rearers need to review milk replacer feeding concentrations to preserve optimum growth rates.
Trouw Nutrition says it is easier to hit growth targets in the summer because 20°C is the thermo-neutral temperature for calf rearing. But as the ambient temperature drops in the winter, the calf needs additional energy to keep warm and to maintain target growth rates, which will fall unless milk powder concentrations are increased. Plans to calve heifers at two years of age can certainly be compromised unless cold weather action is taken.
To illustrate the potential drop in growth rate during colder conditions, the company has developed a new calf growth computer model. The Nutri-Calf program also helps producers evaluate the cost-effectiveness of different winter milk replacer and follow-on feeding regimes.
"Most calf rearers mix replacer with water at a year-round constant rate of 125g/litre," explains Trouw Nutrition technical manager John Twigge. "This rate is fine for most of the year, but during colder conditions growth rates fall below target levels. In order to address the problem, Nutri-Calf shows that milk powder concentrations need to rise to 150g/litre during most winter months and as much as 180g/litre when there is a severe cold period.
"Milkivit Denkamilk milk replacers are high energy, highly digestible products – but even these high quality milks require an increased powder concentration if growth targets are to be maintained for replacement heifer calves on an accelerated development plan."
John Twigge points out that for a heifer to calve and enter the milking herd at 24 months of age, a high level of growth during the pre-weaning milk feeding stage is crucial.
"Accelerating growth in the first six weeks of life is very important – later on it is more difficult, as boosting growth rates at this stage can impair udder development," he maintains.
Further information on the Nutri-Calf model is available from John Twigge on 01606 561287 or by calling the Trouw Nutrition customer services team on 0845 300 5858.
