ABSTRACT
Through marker-assisted selection and transgenic animal technology coupled with embryo splitting and genotyping, the tools needed to create and propagate disease-resistant livestock are at hand. In this chapter, the authors review the genetics of resistance to infectious diseases, their experiences with a disease model, and discuss strategies for mapping and utilizing infectious disease loci to improve animal health and production. Immunologists routinely use quantitative measurements of humoral and cellular immune responses as a measure of immune competence. Levels of responsiveness are generally used as indicators of infectious disease status, depending on the type of response and the antigen in question. Enzootic bovine leukosis (EBL) is a complex lymphoproliferative disease that has a significant impact on the dairy and beef cattle industries worldwide. The development of EBL is associated with chronic infection by the bovine leukemia virus.
