Immunology and Genetics: Phenotypic, Genetic and Epi- genetic Variation of Bovine Immune Responses and Dis- ease Resistance

The immune system integrates innate and adaptive host defense mechanisms and is largely responsible for control of infectious disease. This system is under the tight genetic regulation of hundreds of genes. Some disorders are controlled by one or a few genes, while other more complex infectious diseases are controlled by many genes. Infectious diseases of livestock, including cattle, have become one of the most hazardous and expensive problems facing the agri-food industry. Many of these emerging and re-emerging diseases are zoonotic, causing concern to both animal and human health. Certain infectious diseases can be controlled by traditional methods; however, increasing restrictions on antibiotic use and the sizable costs associated with new drug development are making it more challenging to manage animal health. Therefore, alternative strategies are required for disease prevention that address these concerns for improved food safety and animal well-being. Given the role of the immune system in control of infectious disease, its genetic regulation, and that it is often possible to identify naturally immune individuals within a population, implementing thoughtful genetic strategies to enhance the immune system should help to improve inherent disease resistance. The emerging solutions integrate a variety of molecular and quantitative genetic approaches with both immediate and longterm improvements to animal health. This manuscript describes some of the strategies involving genetic regulation of the immune system.