New concepts in colostrum feeding for dairy calves

Successful transfer of passive immunity (TPI) is essential for calf health and well-being. The current first-milking colostrum feeding guidelines for newborn dairy calves were established more than two-decades ago. The implementation of these guidelines has led to a marked improvement in calf health. Since the guidelines were established, a great deal of additional knowledge has accumulated about bovine colostrum and the benefits of transition milk feeding to newborn calves, particu­larly for the first 5-7 days of life. In addition, the Brix refractom­eter has been validated as a useful on-farm tool to estimate co­lostrum quality. One of the limitations of the current colostrum feeding guidelines is that colostrum with higher Brix scores is fed to calves the same way than colostrum with a lower Brix score (≥ 22%). This prevents calf care providers and managers from taking advantage of colostrum that contains more than 50 g/L of IgG. Identifying colostrum with an IgG concentration of ≥ 75 g/L enables the establishment of colostrum feeding pro­grams that feed a smaller volume of first-milking colostrum but still delivers a sufficient mass of immunoglobulin to have suc­cessful TPI. It will also increase the farm supply of colostrum.