Submitted to: Journal of the American Veterinary Medical Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/28/2011
Publication Date: 5/30/2012
Citation: Donahue, M., Godden, S.M., Bey, R., Fetrow, J., Wells, S.J., Sreevatsan, S., Oakes, M., Stabel, J.R. 2012. Heat-treatment of colostrum on commercial dairy farms: Effects on colostrum characteristics and calf health and performance. Journal of the American Veterinary Medical Association. 95(5):2697-2702. Interpretive Summary: Morbidity and mortality in neonatal calves is a major concern for dairy producers. Evidence suggests that calves can become infected shortly after birth by exposure to pathogens such as Mycobacterium avium subsp. paratuberculosis, Salmonella, and Mycoplasma in either the feces or milk of infected dams, bedding, or cohabitation with other infected animals. These pathogens may be spread to calves through colostrum from sick or infected cows. Some producers have opted to feed colostrum replacers to their calves to avoid the potential spread of disease. However, this is an additional expense that some producers cannot afford. Pasteurization of colostrum is an economical alternative to commercial colostrum products, however, little is known about its effectiveness in destroying pathogens or on the immunoglobulin content. This study demonstrated that pasteurization decreased bacterial counts in the colostrum without destroying the immunoglobulin content. There were no significant effects on calfhood morbidity or growth due to pasteurization of colostrum, however, it did result in increased passive transfer of immunoglobulin. This information provides a useful management tool for dairy producers in allaying the spread of infectious disease to their calves and improving their health.
Technical Abstract: The objectives were to describe the effect of heat-treatment, at 60 deg C for 60 minutes, on colostrum bacteria counts and IgG concentration, and describe the effect of feeding heat-treated colostrum on preweaning calf health and performance. The study design was a randomized controlled clinical trial. Animals used were 1,093 newborn calves on six commercial dairy farms in Minnesota and Wisconsin. Colostrum was collected each day, pooled, divided into two aliquots, and then one aliquot was heat-treated in a batch pasteurizer at 60 deg C for 60 minutes. Newborn calves were removed from the dam within 30-60 minutes of birth, and assigned to be fed 3.8 L of either fresh (n = 520) or heat-treated colostrum (n = 573). Calves were sampled between 1-8 days of age for serum IgG and total protein concentrations. Preweaning treatment and mortality events were recorded. Birth and weaning weights were recorded on three of the farms. Heat-treatment reduced colostrum total plate counts (-2.25 log10) and coliform counts (- 2.49 log10), but, overall, did not affect IgG concentration. However, very high quality batches of colostrum did experience IgG losses after heat-treatment, as compared to low or medium quality batches. Serum IgG and STP concentrations were higher for calves fed heat-treated (vs fresh) colostrum. However, there was no effect of treatment on preweaning treatment, death, or growth rates. Heat-treatment reduced colostrum microbial exposure,while, overall, maintaining IgG concentration, and improved passive transfer status in calves. Though there were no preweaning health or growth benefits identified in this study, this deserves further study.