Effect of feeding heat-treated colostrum on risk for infection with Mycobacterium avium subsp. paratuberculosis, milk production and longevity in Holstein dairy cows

Abstract

Johne's disease, caused by Mycobacterium avium subsp. paratuberculosis (MAP), is one of the most economically important infectious diseases of U.S. dairy cattle. Colostrum is an important source of protective immunoglobulins (IgG) but can be a source of exposure to important pathogens including MAP. Several years ago, we developed a colostrum heat-treatment (HT) protocol (60 QC x 60 min) which preserved important colostral IgG while eliminating most common pathogens and significantly reducing MAP in inoculation studies. Short-term studies reported that calves fed HT colostrum had improved serum IgG levels and reduced morbidity in the preweaning period as compared to calves fed fresh colostrum. However, research has been lacking to investigate whether calves fed HT colostrum also experienced longer term benefits including reduced risk for infection with MAP. The objective of this study was to complete a multi-herd randomized field study to describe the effect of feeding HT colostrum on long-term outcomes including transmission of MAP, milk production and longevity within the herd.