Investigations on genetic disease resistance in swine—A contribution to the reduction of pain, suffering and damage in farm animals

This review deals with genetic disease resistance in pigs as a prospective opportunity to reduce pain, suffering and damage in swine production. Even under favourable terms of housing and management, infectious diseases are wide-spread, and have to be ranked among the major sources for suffering in international pig production. There is abundant variability in resistance/susceptibility of pig populations and breeds to a number of pathogens, including several viruses, bacteria, and parasites, even at similar performance levels. Practical applications of disease resistance in farm animals and established knowledge on disease resistance in swine are presented. The difficulty lies in the identification of carriers of favourable gene variants. With tools and technologies developed in the context of genome projects, new opportunities to dissect the genetic control of host response to infection are presented with QTL analysis of Sarcocystis miescheriana resistance given as an exemplary parasite model: this model demonstrates the existence of outstanding gene loci and their role for polygenic trait variability. It further provides evidence for common mechanisms involved in resistance to different pathogens. Although a long way from the model to markers for disease resistance, pain, suffering, and damage might be reduced by the applications of genetic disease resistance in pig production in the future.