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Interpretive Summary: Concentration and heritability of immunoglobulin G and natural antibody immunoglobulin M in dairy and beef colostrum along with serum total protein in their calves

By: Tess E. Altvater-Hughes, Douglas C. Hodgins, Lauraine Wagter-Lesperance, Shannon C. Beard, Shannon L. Cartwright, and Bonnie A. Mallard

Understanding how breed influences immunoglobulin (Ig) G and natural antibody (NAb) IgM concentrations in colostrum can improve bovine colostrum quality and calf health. Maternal colostral IgG is abundant, persistent, and pathogen specific. Nab-IgM is less abundant but mediates broad, short-lived, nonspecific pathogen protection, and potentially important against septicemia. Colostral IgG and NAb-IgM concentrations were compared between dairy and beef cows and among cross-bred beef cows. Heritabilities were calculated to assess the practicality of selective breeding. Serum total protein (STP) in neonatal dairy and beef calves was estimated using refractometry. Colostrum from beef cows had higher concentrations of IgG than dairy cows. Beef cows with higher Angus ancestry produced colostrum with lower IgG concentrations than other mixed breeds. Heritability of colostral IgG was low (0.04–0.14). Failure of passive transfer was similar in dairy and beef calves, but a significantly larger proportion of beef calves had excellent STP (≥6.2 g/dL). There were no differences in NAb-IgM titers between dairy and beef cows or among beef breeds. Colostral NAb-IgM varied widely among individuals (42-fold) and was moderately heritable (0.11–0.24). These results suggest that selective breeding to improve colostrum quality is feasible and practical to improve calf health.

This article can be found in the Journal of Animal Science.