0178 High immune response technology for use in commercial swine herds: A broad based approach to disease resistance.

Societal concern regarding food safety and animal health are increasing, encompassing issues including the presence of antibiotic residues in meat, antimicrobial resistant organisms and the risk of zoonotic disease. Therefore, effective economic alternatives, with the potential to improve productivity in addition to animal health and robustness, are essential to the industry's continued success. Previous research in pigs has clearly demonstrated favorable responses to breeding pigs for high immune response (HIR). However, this method has not been tested in commercial swine herds. Since the HIR technology identifies animals with increased capacity for immune response (IR) and subsequently increased disease resistance, its implementation and integration into commercial pig breeding programs is expected to bring health and production benefits. The HIR test measures IR to benign and carefully selected test antigens (Ag), one that elicits antibody-mediated IR (AMIR) and another that elicits cell-mediated IR (CMIR). The study objective was to re-establish and refine the HIR test for pigs in a pilot study and then to utilize this test within a commercial facility. Two groups of weaned piglets, 24 piglets/group were HIR phenotyped. Antibody-mediated IR, as measured by antigen-specific ELISA, was greater in the older versus younger test piglets (p < 0.0001, un-paired t test). Cell-mediated IR, was observed by delayed-type hypersensitivity, measured by change in double-skin-fold thickness (DSFT) both 24 and 48 h after intradermal injection of CMIR-associated antigen, and did not differ between test groups. Results indicate it is possible to phenotype and rank pigs for IR using a standardized HIR protocol. Applying this protocol to approximately 3600 weaned F1-barrows from seven different swine genetics companies is now underway as part of a large collaborative Genome Canada project examining associations between IR with swine health, production and genomic information.