Genome-Wide Association Analysis and Genetic Parameters for Egg Production Traits in Peking Ducks

Simple Summary Egg production is a priority for the poultry industry, particularly for traits such as the age at first egg, number of eggs at different stages, and laying rate. Although ducks have higher egg production capabilities than other poultry, the genetic factors influencing these traits have been minimally studied. In this study, we assessed the heritability of these traits and conducted a genome-wide association study, identifying nine significant genetic markers associated with the age at first egg and egg number. The results of the analyses suggest that the candidate variants may have an effect on egg production by influencing ovarian function and oocyte maturation processes. These findings contribute substantially to understanding the genetic foundations of egg production in ducks and provide a basis for future genetic advances in poultry.Abstract Egg production traits are crucial in the poultry industry, including age at first egg (AFE), egg number (EN) at different stages, and laying rate (LR). Ducks exhibit higher egg production capacity than other poultry species, but the genetic mechanisms are still poorly understood. In this study, we collected egg-laying data of 618 Peking ducks from 22 to 66 weeks of age and genotyped them by whole-genome resequencing. Genetic parameters were calculated based on SNPs, and a genome-wide association study (GWAS) was performed for these traits. The SNP-based heritability of egg production traits ranged from 0.09 to 0.54. The GWAS identified nine significant SNP loci associated with AFE and egg number from 22 to 66 weeks. These loci showed that the corresponding alleles were positively correlated with a decrease in the traits. Moreover, three potential candidate genes (ENSAPLG00020011445, ENSAPLG00020012564, TMEM260) were identified. Functional enrichment analyses suggest that specific immune responses may have a critical impact on egg production capacity by influencing ovarian function and oocyte maturation processes. In conclusion, this study deepens the understanding of egg-laying genetics in Peking duck and provides a sound theoretical basis for future genetic improvement and genomic selection strategies in poultry.