Integrated GWAS, Meta-Analysis, and Bayesian Fine Mapping Reveal Novel QTLs and Functional Candidate Genes for Vulva Traits in Large White Pigs_pheno data

The reproductive performance of pigs is crucial for agricultural production, and the vulva traits of sows—such as length, width, and angle—directly impact breeding efficiency. For example, gilts with small or upward-tilted vulva are often culled, limiting the size and efficiency of breeding herds. To improve the retention rate of breeding females, we conducted this study to explore the key genes and genetic mechanisms underlying these traits using genomics. We collected data on vulva traits from 2,197 gilts across three Large White pig populations (from PIC, Topigs, and Canada) and used genome-wide association studies (GWAS) and meta-analysis techniques, combined with Bayesian fine mapping, to systematically identify genetic loci and candidate genes associated with these traits. Through these methods, we discovered several new significant loci and identified potential candidate genes such as SDC2, MTERF3, VIP, POP1, and PSMA1 that may play important roles in regulating vulva traits. These findings provide new insights into the genetic mechanisms of reproductive traits in pigs and offer a vital molecular basis for future breeding programs. By using marker-assisted selection (MAS) or genomic selection (GS), we can more effectively improve vulva traits, thereby increasing the retention rate and productivity of breeding females. This not only enhances the economic benefits of pig farming but also improves animal welfare by reducing the culling of gilts due to reproductive issues.