Colostrum and milk pasteurization improve health status and decrease mortality in neonatal calves receiving appropriate colostrum ingestion

The objective of the study was to evaluate if on-farm heat treatment of colostrum and bulk tank milk can improve calf health status and morbidity and mortality rates during the first 21 d of life in neonatal Holstein calves receiving appropriate colostrum ingestion. A total of 587 calves were randomly assigned to 2 groups of males and females over 18 mo. The nonpasteurized group (n = 287, 143 males and 144 females) was fed frozen (−20°C) colostrum (6-8 L during the first 12 h of life) that was previously reheated up to 40°C. They were also fed refrigerated (4°C) raw milk from the bulk tank that was also reheated up to 40°C (1.8 L every 12 h). The pasteurized group (n = 300, 150 males and 150 females) was also fed colostrum and milk, but both were pasteurized before freezing. Blood samples were drawn from all calves to obtain serum at 2 to 5 d of life. Serum total protein (g/dL) was determined using a commercially available refractometer. Colostrum and milk underwent routine bacteriological analysis to determine total plate counts (cfu/mL) and total coliform counts (cfu/mL). All the calves underwent clinical examination every 24 h during the first 21 d of life. Every day, calves were clinically diagnosed either as being healthy or suffering from respiratory disease, neonatal calf diarrhea, or suffering other diseases. On-farm heat treatment for colostrum and milk reduced total plate counts and total coliform counts between 1 and 2 log10. Pasteurization of colostrum and milk significantly decreased the morbidity and mortality (5.2 and 2.8%) in comparison with calves receiving nonpasteurized colostrum and milk (15.0 and 6.5%), respectively, during the first 21 d of life, even in animals receiving appropriate colostrum ingestion.