Bioactive Components in Colostrum and Milk from Canadian Holsteins Classified as High, Average and Low Immune Responders
Whey proteins protective against mastitis-causing bacteria are present in bovine colostrum and milk. High immune response (HIR) cattle have more robust and balanced antibody-mediated (AMIR) and cell-mediated immune responses (CMIR) compared to Average (A) and Low (L) responders and have lower incidents of mastitis. The hypothesis of this research was that HIR cows have increased concentrations of anti-microbial constituents in mammary secretions compared to A or L responders. The objectives of the study were to quantify total immunoglobulin isotype G (IgG), β-lactoglobulin (β-LG) and lactoferrin in colostrum and milk from cows (n=108) with diverse immune response phenotypes. Results indicated that cattle High (H) for AMIR have significantly greater total IgG and β-LG in colostrum compared to A and L AMIR cows. Breeding for H AMIR cows that produce colostrum with increased concentrations of immunologically active components may provide a method to prevent disease in animals and humans.