Reducing failure of passive immunoglobulin transfer in dairy calves

The dairy calf is unique in that its only source of early immunity is obtained passively from colostrum after birth. There are many factors that impact the early immune status of the dairy calf. Primary factors include the quality of colostrum fed, time of feeding and amount fed. Managing an effective colostrum program should consider these factors, which will result in high level of circulating maternal immunoglobulins present in the blood of the one day old dairy calf. The resulting condition when blood IgG levels are not met is termed failure of passive transfer or FPT. Failure of passive transfer of immunoglobulins results in increased morbidity and mortality for the young calf thus is of great economic importance to the dairy industry. Increased exposure from pathogens makes calves prone to FPT and more susceptible to morbidity and mortality. Recent research has shown methods to pasteurize colostrum to reduce bacterial loads in colostrum. Pasteurization has shown the additional effects of improving immunoglobulin absorption by the calf. The objective of this review is to summarize the literature of achieving proper levels of passive immunity in calves, including the importance of colostrum for the neonate, IgG absorption, and effects of pasteurization on bacterial load, and IgG levels.