The impact of amount and quality of colostrum and subsequent transition milk on calf health and growth

Abstract Text: In the US, the current “gold standard” is to deliver colostrum to newborn calves at 10% of BW within the first 2h of life. In practice, many farmers simply offer calves 1.89 L of colostrum within 12 h of birth. For a 43 kg calf, this is about 4.5% of the calf’s weight – not even half of the recommended amount. Colostrum ingestion is critical for passive transfer of immunity in the form of immunoglobulins (Ig).  Researchers in Ireland examined the effects of feeding different volumes of colostrum (7, 8.5, or 10% of BW within 2h of birth) and subsequent feedings (0, 2, or 4) of transition milk on serum IgG and health status. Ninety-nine calves were enrolled. They found that calves fed 8.5% of BW within 2h of birth achieved the highest levels of IgG transfer. Following the initial feeding of colostrum, offering transition milk to calves appears to have positive impacts on calf health. Calves fed 2 or 4 subsequent feedings of transition milk, seemed to have a lower risk of getting assigned poor nasal and eye scores (Conneely et al., 2014). The researchers were right to focus on measurement of serum IgG concentration in their project calves, as serum IgG is a major indicator of calf health because calves are born agammaglobulinemic. Therefore, when calf Ig measurements are obtained after consumption of colostrum, they reflect Ig content of colostrum and absorptive ability of the calf’s small intestine. Colostral Ig absorption is highest in the first 24h of life and declines sharply; this has to do with permeability of the calf’s small intestine to large molecules such as Ig. This process is termed passive transfer of immunity and it is key in protecting the calf against pathogens that the dam was previously exposed to, prior to the calf’s own immune system maturing and becoming more functional (Godden, 2008). In conclusion, if colostrum quality is sufficient and calves are managed properly, calves seem to excel at 8.5% of their body weight at birth and when offered a few feedings of transition milk will have improved health and be less prone to disease in the first three to four weeks of life (Conneely et al., 2014).  For a 43kg Holstein calf, this equates to 3.66 L of colostrum.

Keywords: dairy calf, immunoglobulin