Helping Farmers Make Better Herd Management and Breeding Decisions High Immune Response Technology Identifies Animals with Superior Immunity, say Researchers By Karli Longthorne
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educing disease and improving animal health have been long-standing goals for the Ontario beef industry and its farmers, particularly with the high incidence of bovine respiratory disease (BRD). BRD—a disease in the upper or lower respiratory tracts caused by bacterial or viral pathogens— has been identified by the Canadian Cattlemen’s Association as the most common and costly disease affecting the North American beef industry. BRD rates remain unchanged despite advancements in medicine and Canadian beef production management strategies. That’s where University of Guelph Prof. Bonnie Mallard, Department of Pathobiology at the Ontario Veterinary College, and a team of researchers, including Dr. Julie Schmied and Dr. Douglas Hodgins, as well as graduate students Nasrin Husseini, Shannon Beard and Shannon Cartwright, come in. The Mallard lab was the first to develop a genomics test for Holsteins that determines associations between an animal’s specific set of immune response genes and their ability to fight disease, using High Immune Response (HIR™) technology. Now this group is looking to adapt this technology for use in Angus beef cattle. The HIR technology identifies animals with superior immune responses by evaluating antibody and cell-mediated immune responses, allowing for the calculation of an estimated breeding value or expected progeny difference for total immune response for each animal. This means cattle farmers can determine early in life which animals have superior health and which are at increased disease risk. They will also be able to select and breed animals better able to fight disease
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by selective breeding of high immune responders, while fostering healthier herds. “Our research makes a difference for producers, animals and consumers. Producers will save time and money on the treatment of sick animals by minimizing the use of antibiotics and other therapeutic interventions,” says Mallard. “By bringing the HIR technology into the beef market, consumers can feel good knowing that their food came from naturally healthy animals that were raised in a healthy and sustainable manner.” A genomics test similar to that used for dairy cattle will be valuable to the beef industry because immune response traits have not yet been incorporated into breeding programs for beef cattle. Their inclusion has the potential to improve overall animal health and enhance disease resistance, including within the context of climate change and calf health. Climate change is also taking a toll on the livestock industry, making it difficult for livestock to adapt to the constantly changing environment, particularly global warming. The HIR phenotypic test and the researcher’s genomics test may also help identify cattle who are better able to adapt to climate change, as preliminary research in both beef and dairy cattle performed at the Elora Research Station suggests cows that have high immune responses could better adapt to heat stress. The HIR tests are expected to allow beef producers to identify the traits in beef cattle that could improve calf health. Previous research shows that dairy cows that are high immune responders have better quality colostrum, providing their calves colostrum with greater amounts of antibody. Immune response is a moderately heritable trait,
