Genetic Basis of Growth and Carcass Traits in Sansui Duck Identified Through Genome-Wide Association Analysis.

Abstract

The Sansui duck is a valuable Chinese genetic resource. However, incomplete exploration of its genetic resources has limited the full utilization of its genetic potential. This study systematically evaluated the growth and carcass performance in 305 Sansui ducks and explored their genetic basis through genome-wide association studies (GWAS). Body weight (recorded biweekly from 0 to 20 weeks), body measurement traits, and carcass yield traits (measured at 20 weeks) were collected. Growth curve analysis revealed a relatively slow growth rate, with early growth occurring from 0 to 14 weeks and a critical period for weight gain observed at 8-10 weeks. Sansui ducks exhibited small body size with favorable meat production traits: half-eviscerated yield percentage (HEYP) and eviscerated yield percentage (EYP) both above 70%, while breast muscle percentage (BMP) and leg muscle percentage (LMP) reached 11.99% and 11.01%, respectively. SNP-based heritability estimates indicated moderate to high heritability for growth and slaughter traits. GWAS identified 222 SNPs associated with growth and slaughter traits, which were annotated to 53 candidate genes, including EFEMP1, SKAP1, and MYO19. Linkage disequilibrium (LD) analysis further pinpointed two key genomic regions on chromosome 28 (1-200 kb and 250-320 kb) influencing multiple traits. These regions harbor critical candidate genes, including the HOXB family and IGF2BP1, which play important roles in regulating skeletal development, energy allocation, and growth rhythm in poultry. These findings enrich the genetic resource database of the Sansui duck and provide an important theoretical basis for further elucidating the genetic foundation of its growth and carcass performance.