Genome-wide association analysis of residual feed intake in Junmu No. 1 White pigs.

Residual feed intake (RFI) is a measure of feed efficiency. Pigs with low RFI have reduced feed costs without compromising their growth. For marker-assisted selection, it is helpful to identify genes or genetic markers associated with RFI in animals with improved feed efficiency at an early age. Using Illumina's PorcineSNP60 BeadChip, we performed a pilot genome-wide association study of 217 Junmu No. 1 white male pigs phenotyped for RFI. Two-step and one-step methods were used separately to identify associated SNPs. Both methods obtained similar results. Twelve SNPs were identified as significantly associated with RFI at a Bonferroni adjusted P-level < 9.7 x 10(-7), and 204 were found to have suggestive (moderately significant) association with RFI at P < 5 x 10(-5). NMBR, KCTD16, Delta SGR1, PRKCQ, PITRM1, TIAM1 and RND3 were identified as candidate genes for RFI.