biostudies-literatureUnknown103(6)Chen AThe age of first egg (AFE) in chicken can affect early and even life-time egg production performance to some extent, and therefore is an important economic trait that affects production efficiency. To better understand the genetic patterns of AFE and other production traits including body weight at first egg (BWA), first egg weight (FEW), and total egg number from AFE to 58 wk of age (total-EN), we recorded the production performance of 2 widely used layer breeds, white leghorn (WL) and Rhode Island Red (RIR) and estimated genetic parameters based on pedigree and production data. The results showed that the heritability of AFE in both breeds ranged from 0.4 to 0.6, and AFE showed strong positive genetic and phenotypic correlations to BWA as well as FEW, while showing strong negative genetiPoultry science103627https://www.ebi.ac.uk/biostudies/studies/S-EPMC11015155biostudies-literatureGenetic parameter estimation and molecular foundation of chicken egg-laying trait.PMC11015155Ren XMei XGuo XJiang RWang GWang HCheng XZhao XGuo MChen AWen JZhang YQu LZhang XJiang XWei GWang XNing ZYu XfalseGenetic parameter estimation and molecular foundation of chicken egg-laying trait.The age of first egg (AFE) in chicken can affect early and even life-time egg production performance to some extent, and therefore is an important economic trait that affects production efficiency. To better understand the genetic patterns of AFE and other production traits including body weight at first egg (BWA), first egg weight (FEW), and total egg number from AFE to 58 wk of age (total-EN), we recorded the production performance of 2 widely used layer breeds, white leghorn (WL) and Rhode Island Red (RIR) and estimated genetic parameters based on pedigree and production data. The results showed that the heritability of AFE in both breeds ranged from 0.4 to 0.6, and AFE showed strong positive genetic and phenotypic correlations to BWA as well as FEW, while showing strong negative geneti2024-01-01T00:00:00Z2024 Mar2025-04-26T20:04:41.793Z2025-04-06T16:19:59.526ZS-EPMC110151553859355110.1016/j.psj.2024.103627