POSSIBILITIES OF SELECTION ON HIGH-RESIST ANCE IN PIGS BASED ON IMMUNOLOGICAL PARAMETERS

Disease resistance results from different processes which partly are i mmunological in nature. Immunological processes can be subdivided into innate (non-specific) resistance (phagocytosis) and acquired resistan ce. The latter can be subdivided in cellular and humoral immunity. The se three compartments of the immune system do not act independently bu t are complementary. Parameters for each of the compartments have a ge netic basis, and expression is affected by many genes, some of which a re known. Experimental results suggest that especially aspects of inna te disease resistance (the killing capacity of phagocytes) are negativ ely correlated with humoral immune response. Comparison of pig breeds supports this idea. On the other hand selection experiments show that simultaneous improvement of various aspects of the immune system is po ssible. Consequently, selection programmes should utilize index select ion including parameters of all three compartments. Research in mice a nd various farm animal species studied genetic aspects of immune param eters. Little attention has been paid to the relationships between imm une responsiveness and resistance to specific infections. To support t he implementation of selection programmes for disease resistance in pi gs, further experiments using e.g. mice as a model and the design of s imulation models are useful.