Immune management and vaccination of the preweaning beef calf
Keywords:colostrum, antibody, respiratory disease
Ensuring health of preweaning calves requires attention to colostrum intake and nutrition of the dam and calf, and targeted use of vaccination. Colostrum intake that leads to optimal, and not just adequate, passive immunity can improve calf health. The neonatal calf has a functional immune response, and calves can respond to vaccination in the first week of life. Maternal antibodies do not always suppress response to vaccination, but intranasal routes of vaccination may more effectively prime immunity in the first month or two of life, when maternal antibodies are at the highest concentration. Either intranasal or parenteral vaccines can be effective to prime immunity in calves at 90 to 120 days of age. In calves, booster doses are particularly important to ensure immunity, as not all calves will be prepared to respond optimally at the time of their first vaccination. Field trials indicate that preweaning vaccination can sometimes improve health postweaning, but few field trials have evaluated the effects of preweaning vaccination on preweaning disease. Challenge studies and research measuring immune function provide support for vaccination to prevent preweaning disease, but the evidence quality is not strong. More field trials testing vaccination of preweaning calves to prevent preweaning disease are needed.