Calf feed comprises primarily colostrum, and thereafter milk (replacer) and roughage and concentrate. The condition is that the quality is good, hygienic working conditions are observed and that quantities are sufficient. It is therefore important for optimal calf rearing to select the right feeding schedule.
Feeding calves begins with providing mother’s milk. At birth, the calf hasn’t yet produced any antibodies and is therefore not protected against different pathogens. The cow does not provide these antibodies (immunoglobulins) via the placenta. So the immunoglobulins have to come from the mother’s milk. Immunoglobulins are large protein chains that can pass through the intestinal wall for the first few hours after birth. In addition to the immunoglobulins, it is also crucial to the calf’s survival to administer proteins and fats via the so-called ‘first milk’. Table 2 shows the recommendations regarding colostrum supply (Source: GD Animal Health Deventer).
The colostrum must of course be of good quality, but this is not always the case in practice. A good way to measure the quality is to use a refractometer. This determines the percentage of dry feed of the first milk, and the related number of immunoglobulins. A Brix value of well over 21 represents good-quality colostrum. Below 21 means mediocre or poor quality.
If the colostrum is of insufficient quality, it can be enriched with Topro Colostrum Mix to improve the quality. Figure 1 (Veeteelt 2014) shows how important good-quality colostrum (high share of IgG) is for a calf. Good colostrum supply and quality has a positive effect on growth in the first few weeks, the number of days of diarrhoea, mortality and veterinary costs.