Estimation of genetic parameters and breeding value accuracy for growth and egg production traits in Korean native chicken pure lines

Korean native chickens (KNC) have a rich history and are highly regarded by Korean consumers owing their distinct flavors and textures. However, their slow growth and limited egg production pose challenges compared with commercial chicken breeds. To address these limitations and enhance economically important traits, such as growth and egg production, understanding their genetic foundations is necessary. We studied five KNC lines (F, H, S, W, and Y) and assessed them for weight at 8, 10, and 12 weeks of age and the total number of eggs laid. The analysis incorporated pedigree data from 50773 chickens from Hanhyup Breeder chickens. Line F showed a mean inbreeding coefficient of 0.0017, whereas the other lines exhibited lower mean values ranging from 0.0005 to 0.0028, indicating that the inbreeding levels were within an acceptable range and considered safe from extinction. The average relatedness was 0.46-1.88 % among the studied lines. Heritability estimates for growth traits in line F were relatively high (ranging from 0.32 to 0.35), indicating a significant contribution of additive genetic variance and suggesting potential for genetic improvement through performance testing. However, the heritability of the egg production trait was low (0.07-0.16), indicating a greater role of non -genetic factors in explaining phenotypic variation. Management strategies should focus on improving these characteristics. Genetic correlations revealed strong positive associations between selected growth traits (up to 0.98), whereas all growth traits were negatively correlated with the total number of eggs laid. This suggests shared genetic influences on growth traits and highlights the potential for improving multiple correlated traits by enhancing the genetic performance of one trait. We also assessed the accuracy of estimated breeding values (EBVs), which ranged from 0.55 to 0.69 and 0.42 to 0.58 for growth traits and egg production trait, respectively. These moderately accurate estimates indicated that EBVs can effectively indicate the true breeding value of an animal. To improve accuracy, it is essential to maintain reliable phenotypic and pedigree records, as well as increase the number of animals in the flock. Therefore, this study provides insights into the genetic parameters and breeding value accuracy of growth and egg production traits in KNC, facilitating future genetic improvement programs for these economically important traits.