中国荷斯坦牛产后0～35d繁殖疾病遗传参数估计

Estimation of Genetic Parameters of Reproductive Diseases within 0-35 Days after Calving in Chinese Holsteins

旨在估计中国荷斯坦牛产后0～35d的繁殖疾病遗传参数。本研究收集了1993-2017年间北京地区27个场中国荷斯坦牛产后0～35d25 026条繁殖疾病记录,统计分析发病规律,采用阈模型和线性模型,以场年、胎次和产犊季节为固定效应,个体加性遗传效应和永久环境效应为随机效应得到遗传参数来探究中国荷斯坦牛产后0～35d繁殖疾病遗传规律,同时尝试单独对子宫疾病进行遗传参数估计。结果显示,奶牛产后0～35d繁殖疾病记录占整个泌乳期繁殖疾病记录的54%;使用线性模型和阈模型所得奶牛产后0～35d遗传力分别为0.015 2(0.001 9)和0.094 4(0.01),使用SAS计算两个模型繁殖疾病EBV排名秩相关达95%(P<0.01);在繁殖疾病中,子宫疾病占48%,且主要集中于产后0～35d,利用线性模型估计得到产后0～35d子宫疾病遗传力为0.010 7(0.001 6)。根据线性模型得到的EBV计算繁殖疾病遗传趋势,发现自2000年以来,公母牛繁殖疾病、子宫疾病估计育种值均呈现下降趋势。本研究结果可为中国荷斯坦牛繁殖疾病的遗传育种工作提供参考。

The aim of this study was to estimate the genetic parameters of reproductive diseases within 0-35 days after calving in Chinese Holsteins.Twenty five thousand and twenty-six reproductive diseases records within 0-35 days after calving from 27 farms from 1993 to 2017 were collected,threshold model and linear model were adopted to estimate the genetic parameters.Farm-year,parity and calving season were considered as fixed effects,additive genetic effect and permanent environmental effect as random effect to explore the genetic regularity of reproductive diseases within 0-35 days after calving in Chinese Holsteins.The genetic parameters of uterine diseases were estimated using the same model.The results showed that 54% reproductive diseases records of dairy cows happened within 0-35 days after calving comparing to total reproductive diseases records in the whole lactation.The estimated heritabilities of reproductive diseases within 0-35 days after calving using linear model and threshold model were 0.0152(0.0019)and 0.0944(0.01),respectively.The rank correlation of estimated breeding value(EBV)derived from the two models for reproductive diseases was 95%(P<0.01).Uterine diseases accounted for 48% of reproductive diseases and mainly occurred during 0-35 days after calving,and the estimated heritability of uterine diseases within 0-35 days after calving by linear model was 0.0107(0.0016).There was a decrease tendency of EBV both male and female since 2000 based on the results of linear model.The study may provide a reference for the genetic selection and breeding for reproductive diseases in Chinese Holsteins.