Association study between single nucleotide polymorphisms in candidate genes and reproduction traits in Italian Large White sows

In this study we evaluated the effects of candidate single nucleotide polymorphisms (SNPs) on reproduction traits of Italian Large White (ITLW) purebred sows at first parity. We genotyped DNA samples extracted from hair roots of 1,548 sows distributed across six farms located in Northern Italy. A total of 21 SNPs in 20 genes, selected from literature, were genotyped. Seventeen SNPs showed minor allele frequencies >0.05 in the ITLW breed. Association analyses were performed with the following traits: number of piglets born alive (NBA1), number of stillborn piglets (NSB1), total number born (TNB1), NBA1 estimated breeding values (EBVs) and NBA1 random residuals (RRs). SNPs in BMPR1B, FUT1, GPX5, RBP4 and TGFBR1 genes showed significant association (P nominal <0.003) with NBA1 EBVs. Additional three markers (EPOR, GDF9:c.1806T>C and STAT5B) presented suggestive effects (P nominal <0.03) on NBA1 EBVs. The BMPR1B SNP showed a trend (P nominal from 0.01 to 0.05) on NBA1, NBA1 RRs and TNB1. This gene could be a promising candidate for additional investigations aiming to confirm evidences reported in this study.