A Genome-Wide Association Study Exploring the Genetic Architecture of Eggshell Quality in Chinese Wenshang Barred Chickens

Eggshell quality is a critical trait in poultry production, as it directly influences economic outcomes. The genetic architecture underlying this trait remains poorly characterized. In this study, we conducted a genome-wide association study (GWAS) on Chinese Wenshang Barred chickens at 43 weeks of age to identify genomic loci and candidate genes associated with eggshell quality. This analysis revealed 87 significant SNPs and 14 candidate genes. Genes including MC2R, CDC73, LYSMD2, TNFAIP8L3, and CYP19A1 were associated with eggshell weight; PHEX, ATM, STXBP6, SLIT3, and RALY with eggshell thickness; and SOCS5 and ATG4C with eggshell strength. Notably, three SNPs emerged as the most promising markers for eggshell quality, though their functional roles in laying hens require further investigation. This study advances our understanding of the genetic basis of eggshell quality and holds significant practical implications for improving this trait through targeted breeding strategies.