154 A genetic marker for PRRS resistance has no adverse effect on economically important traits in pigs

Abstract

Abstract Porcine Respiratory and Reproductive Syndrome (PRRS) is a very costly viral disease of pigs. A genetic marker for host response to PRRS on chromosome 4 (rs80800372, (WUR)) could be used to select for resilience to PPRS. However, before including WUR in selection, it is necessary to know effects of WUR on economically important traits without PRRS. A dataset with both genotypes and phenotypes on purebred Duroc (D), Landrace (L), Yorkshire (Y) and crossbred (LY or DLY) pigs was used. A total of 20 traits were tested. Sow reproduction and litter traits were available on > 13,000 D, L and Y and 1,549 LY sows. Growth and ultrasound traits were recorded on >35,000 D, L and Y and 2,622 DLY pigs. Daily feed intake (70-120kg) was from 4,133 Durocs. Carcass and meat quality traits were from 2,184 Durocs, 1,160 Yorkshires and 2,184 DLY pigs. All animals were genotyped using a custom SNP chip ( > 55K) including WUR. Analyses were done within each breed using an animal model. WUR was fitted as a fixed effect by classifying pigs with one or two favourable alleles (B) into one group and others into a second group. Contemporary group, parity, litter, lactation length and net fostering effects were considered depending on the traits. Relationship matrices were constructed using pedigree in purebreds and genotypes in crossbreds. WUR had no significant ( P >0.05 ) effect on any trait, except for number of pigs alive at 24hrs in Y and ultrasound loin depth in D and Y ( P< 0.05 ) but the favorable WUR allele also had favorable effects on these two traits. These results were similar to the report by Dunkelberger et al. (J. Anim. Sci. 2017, 95: 2838). In conclusion, WUR had no adverse effects on any trait and can be used to select pigs with increased resilience to PRRS.