Submitted to: National Pork Board Web Site Publication Type: Popular Publication
Publication Acceptance Date: December 22, 2003
Publication Date: May 10, 2004
Citation: Lunney, J.K. 2004. Are there immune gene alleles that determine whether a pig will be healthy?. National Pork Board Web Site . National Pork Board Press, Des Moines, IA. p. 63-72.
This presentation addresses issues of pig health. It asks whether
immunologists and geneticists will be able to use modern genomic
approaches to identify pigs with improved disease resistance or,
basically, pigs that will be "healthier." Other presenters at this
meeting addressed areas of pig diseases and approaches used to map genes and disease resistance traits in dairy cows and poultry. Most scientists would agree that it is not possible to select pigs which resist all diseases. Like humans, genetic alleles determining inheritance of many congenital diseases have been identified; breeders now have molecular tests for defects such as porcine stress syndrome. Data on genetic susceptibility to different cancers and autoimmune diseases in humans are being accumulated. But there is limited information on natural, or genetically encoded, infectious disease resistance. This paper addresses the more difficult issue of resistance to infectious diseases in pigs. It reviews numerous areas where genomic control points could be identified: neonatal development of immune tissues, innate immunity and acquired
immunity. For each area an overview of immunity is presented and
complexities and options for selection for "improved traits" are
reviewed. Current progress on genetic selection and mapping for immune traits as well as disease resistance markers are summarized. Integrated studies targeting the genetics of immunity and disease
resistance are essential for improved pork quality. As scientists
identify breeding stock that is healthier, by virtue of its innate or acquired disease resistance properties, they will also help decrease dependence on antibiotics. Genetic studies of immunity and disease resistance should also reveal novel protective host effector mechanisms. Investigations of such novel mechanisms may lead to new genetic stock resistant to specific diseases; additionally, they may reveal details of disease prevention pathways and lead to development of new biotherapeutics or alternate immune-based disease control mechanisms. Disease resistance studies which incorporate specific production parameters and nutritional concerns in their design will help producers select the breeding stock which possesses the necessary immunity and disease resistance parameters while retaining important production traits. Overall, enormous benefit can come from such studies.