Grant: Collaborative Research and Development Grants

Diseases of dairy cattle adversely affect meat and milk quality. Our research demonstrates that high immune response (HIR) cattle have many health advantages, including better quality colostrum/milk. HIR technology is marketed by our partner, the Semex Alliance as Immunity+. While many advantages of HIR exist, including enhanced antigen-specific antibody and cell-mediated immune responses, there are more to discover, particularly in relation to colostrum. Colostrum is the first milk produced from the mother that protects newborns from disease. HIR cows have enhanced antigen-specific antibody which they pass to their calves via colostrum. There are many other components of colostrum apart from antigen-specific antibody associated with disease protection, including ""natural"" antibody. Natural antibody is present in circulation without previous exposure to pathogens and provides part of the first-line of innate defense. Natural antibodies and other natural defense molecules, known as defensins, also have not been investigated in the context of colostrum and HIR high immune responders. Examining antigen-specific antibody to vaccines, natural antibody and defensins in colostrum/milk from high versus average or low immune responders, as well as variation in the expression of genes that code for a receptor important for the circulation of antibody, called FcRN (Fc Receptor Neonatal), will be the focus here and may reveal a potential method to improve neonatal calf health.*In addition to genetic regulation of immunity, there are epigenetic mechanisms, such as micro RNA (miRNA) found in bovine colostrum that influence the development of the neonatal immune system. Preliminary data from our group indicates that HIR cows have greater quantities of specific miRNAs with the potential to impact neonatal immunity. Therefore further investigation of immuno-regulatory miRNA in the context of HIR is also warranted. *