Genome-wide Association Study of Host Response to Experimental Infection with the PRRS Virus in Pigs

Porcine Reproductive and Respiratory Syndrome (PRRS) represents the most costly disease in the US pig industry. Caused by an RNA virus, vaccination strategies have generally been ineffective. Thus, to investigate opportunities for genetic improvement of pigs for increased resistance or tolerance to the PRRS virus, the PRRS Host Genetics Consortium (PHGC) was established. Among others, the PHGC involves experimental challenge of piglets provided by commercial breeding companies with a specific strain of the PRRS virus shortly after weaning, evaluating piglet response in terms of viremia and weight gain, genotyping each piglet with the Porcine 60K SNP panel, and conducting genome-wide association studies to identify genomic regions associated with host response. The purpose of this presentation will be to review results of the first five challenge trials of 200 piglets each and to discuss future plans and implications.