This study aimed to evaluate the genetic parameters of longevity traits of Holstein cows and provide insights for improving production performance and implementing balanced breeding.The culling records for 19 756 Holstein cows from 9 large-scale dairy farms in Jiangsu during year 2017 to 2023 were collected,and the longevity and elimination situation of cows was analyzed.The significance test for fixed effects including factors like farms,birth year,birth season and age at first calving was conducted using the GLM program in R software.The variance components and calculated heritability for longevity traits were estimated in BLUPF90.The breeding values for longevity traits of Holstein cattle in Jiangsu were evaluated and the genetic trend was depicted.The results showed that the average herd life of adult cows in large-scale farms in Jiangsu was 1 640.87 d,the production life was 917.15 d,and the average culling parity was 2.60.The longevity traits were found to had relatively low heritability,ranging from 0.07 to 0.15.The genetic and phenotypic correlations between these 7 longevity traits(herd life,production life,culling parity,L1-L4)exhibited moderate to high correlations,ranging from 0.27 to 0.99.Notably,the correlation between herd life and productive life was closer to 1.Moreover,the genetic trend for longevity traits was assessed through breeding values,and which had shown a deceleration in recent years,indicating a reduced rate of genetic improvement.This study systematically analyzed the genetic variation for longevity traits using data from 9 large-scale farms in Jiangsu.These findings can provide insights for the genetic evaluation and making breeding decisions for longevity traits in the future.
关键词
荷斯坦牛/长寿性状/遗传力/遗传相关/育种值
Key words
Holstein cows/longevity trait/heritability/genetic correlation/breeding value
维普
万方数据