摘要
旨在研究山东省荷斯坦牛乳尿素氮的遗传参数及其与产奶性状(产奶量、乳蛋白率、乳脂率)和体细胞评分的遗传相关和表型相关.本研究使用山东省2016-2022年间15 497头头胎荷斯坦牛的99 732条DHI记录数据,将场、产犊年、产犊季节、产犊月龄、泌乳阶段效应作为固定效应,以个体加性遗传效应以及永久环境效应作为随机效应,利用DMU软件,采用AI-REML结合EM算法配合重复力模型进行遗传参数估计.结果显示:乳尿素氮、产奶量、乳脂率、乳蛋白率和体细胞评分的遗传力分别为0.129、0.252、0.188、0.257、0.110,均为中低遗传力;重复力分别为0.132、0.513、0.231、0.320、0.339,除乳尿素氮外,均为中等重复力;乳尿素氮与产奶量、乳脂率、乳蛋白率和体细胞评分的遗传相关分别为:-0.02、0.20、0.04和-0.11;表型相关分别为:0.01、0.05、0.01和-0.015近乎为0.结果表明,乳尿素氮与产奶性状及体细胞评分存在较弱遗传和表型相关,在不影响产奶性状的前提下,对乳尿素氮这一性状进行选择是可能的,同时可以将其纳入荷斯坦牛育种工作中.
Abstract
The aim of this study was to study the genetic parameters of milk urea nitrogen and its genetic and phenotypic correlations with milk production traits(milk yield,milk protein percent-age,milk fat percentage)and somatic cell score in Holstein cows in Shandong Province.In this study,we used data from 99 732 DHI records of 15 497 first-calf Chinese Holstein cows in Shan-dong Province between 2016 and 2022,and the effects of farm,calving year,calving season,cal-ving age in months,and stage of lactation were used as fixed effects,and individual additive ge-netic effects as well as permanent environmental effects were used as random effects,the genetic parameters were estimated using the DMU software,and AI-REML combined with the EM algo-rithm with the repetition force model for genetic parameter estimation.The results showed that the heritability of milk urea nitrogen,milk yield,milk fat percentage,milk protein percentage and somatic cell score were 0.129,0.252,0.188,0.257,0.110,respectively,which were low to medium heritability;the repeatability was 0.132,0.513,0.231,0.320,0.339,respectively,which were medium repeatability except for milk urea nitrogen;the genetic correlation between milk urea nitrogen and milk yield,milk fat percentage,milk protein percentage and somatic cell score had genetic correlations of-0.02,0.20,0.04 and-0.11,respectively;and phenotypic correlations of 0.01,0.05,0.01 and-0.015 were near zero,respectively.The results indicate that milk urea nitrogen has a weak genetic and phenotypic correlation with milk production traits and somatic cell score.Therefore,it is feasible to select for milk urea nitrogen without adversely affecting milk production traits,as well as incorporating it into Holstein cattle breeding efforts
维普
万方数据