Background: Pigs are one of the most important livestock species for providing meat products in the world. Deciphering the genetic architecture of feed efficiency-related traits is beneficial to improve the genetic progress of these traits and save the total cost of pork production. However, the genetic architecture of feed efficiency-related traits remains unclear. Methods: To address this problem, we collected 1301 genotyped Yorkshire pigs with three feed efficiency-related traits, including days at 100 kg (DAYS₁00), backfat thickness at 100 kg (BFT₁00), and feed conversion ratio from 30 to 100 kg (FCR₃0₁00), to explore the genetic parameters and genetic basis of these traits. Results: The heritability of DAYS₁00, BFT₁00, and FCR₃0₁00 was 0. 25 ± 0. 04, 0. 40 ± 0. 05, and 0. 23 ± 0. 04, respectively. Additionally, BFT₁00 and DAYS₁00 had a weak negative genetic correlation (−0. 01 ± 0. 12), while trait FCR₃0₁00 showed a positive genetic correlation with DAYS₁00 (0. 51 ± 0. 11) and BFT₁00 (0. 28 ± 0. 12). A genome-wide association study identified 7, 5, and 4 SNPs independently associated with BFT₁00, DAYS₁00, and FCR₃0₁00, respectively. Further analysis found that the candidate gene ETV4 was significantly associated with DAYS₁00 and the candidate gene ENSSSCG00000045751 was associated with FCR₃0₁00. The functional annotation of candidate genes was enriched in the bile acid metabolic process and protein ubiquitination terms. Conclusions: This study discovered 16 quantitative trait loci associated with feed efficiency-related traits, providing a comprehensive insight for understanding the genetic basis of feed efficiency-related traits in pigs. The candidate genes, such as ETV4 gene in DAYS₁00, CAMK1D gene for BFT₁00, and ENSSSCG00000045751 gene for FCR₃0₁00, could be used for further investigation.
Lin et al. (Fri,) studied this question.