Estimation of genetic parameter for wool traits in FGF5 gene-edited Chinese Merino sheep

Introduction We previously edited the fibroblast growth factor 5 ( FGF5 ) gene to improve wool quality and increase wool production. However, the current population of FGF5 gene-edited sheep faces low breeding efficiency during expansion. To address this challenge, we constructed multi-trait animal models to estimate the genetic parameters of key wool traits. Methods Phenotypic data were collected from 281 yearling FGF5 gene-edited fine-wool sheep at the Sheep Breeding Base of the Xinjiang Academy of Animal Science. Two relationship matrices were constructed: one based on pedigree information (LM_A) and another combining pedigree and genomic information (LM_H). Genetic parameters were estimated for staple length (SL), straightened length (TL), fiber diameter (FD), and greasy fleece weight ( GFW). Results Heritability estimates for SL (0.401, 0.380), TL (0.265, 0.309), and FD (0.240, 0.302) using LM_A and LM_H were moderate, while GFW (0.153, 0.164) showed low heritability. Strong positive genetic correlations were observed among SL, TL, and GFW, with correlation coefficients ranging (0.518 - 0.969). Compared with LM_A, LM_H produced heritability estimates with smaller standard errors. Discussion Overall, the LM_H approach under the multi-trait animal model provides more accurate estimates of genetic parameters for wool traits. Our findings provide a basis for genetic estimation in FGF5 gene-edited fine-wool sheep and support the development of genetic evaluation for this population.