中国荷斯坦牛头胎产奶量和乳成分遗传参数估计

Genetic Parameters for Test-Day Milk Yield and Milk Composition in Chinese Holstein First Parity

本研究旨在应用随机回归测定日模型对奶牛生产性状进行遗传评估。收集河南省内17个牧场2008年1月2017年5月共16 335头奶牛头胎174 634条生产性能记录,建立筛选标准对数据进行质控。遗传评估采用随机回归模型,场-测定日为固定效应,以固定回归拟合产犊月龄效应,随机效应包括加性遗传和永久环境效应。固定和随机回归均采用4阶Legendre多项式。结果表明:中国荷斯坦牛头胎测定日产奶量、乳脂率、乳蛋白率、体细胞评分总遗传力分别为0.144 1、0.289 1、0.373 2和0.089 8。本研究为区域性中国荷斯坦牛的遗传评估平台建设和育种规划制定奠定基础。

The aim of this study was to estimate the genetic parameters for first parity production traits in Chinese Holstein using random regression test-day model.A data base which including 174 634 test-day records for first parity of 16 335 cows from 17 herds between 2008 to May 2017 were collected from Henan DHI center.After quality control,the data were used to genetic evaluation.Random regression test-day model were used in genetic evaluation.In the random regression test-day model,herd-test-day were treated as fixed effects,age at calving as a fixed regression covariate,additive genetic effects and permanent environmental effect as random effects.For the fixed regression and random effects,Legendre polynomials of order 4 were chosen.The results showed that the heritability of first parity milk performance traits were 0.144 1 for test-day milk yield,0.289 1 for fat%,0.373 2 for protein%and 0.0898 for somatic cell score.The results set the foundation for regional genetic evaluation system and breeding program design of Chinese Holstein.