荷斯坦杂种牛繁殖性能遗传改良效果评估

Evaluation of genetic improvement of reproductive performance on crossbreds of Holstein cattle

为评估种公牛对荷斯坦杂种牛繁殖性能的遗传改良效果,以荷黄低代杂种、荷黄高代杂种和纯种荷斯坦牛3种奶牛群体共计293头奶牛为研究材料,利用北美荷斯坦验证种公牛对不同奶牛群体进行杂交改良。根据系谱信息追踪各群体的后裔,统计整理空怀天数(DO)、产后第一次配种天数(DFB)和初产月龄(AFC),用最小二乘法分析群体、世代、配种年份、母本和胎次与繁殖性能的相关性。结果表明,高代杂种和低代杂种的DO显著低于纯种(P<005);低代杂种DFB显著低于纯种(P<005),高代杂种在数值上有低于纯种的趋势。1世代,高代杂种和低代杂种DFB显著低于纯种(P<005);高代杂种AFC显著低于低代杂种(P<005),高代杂种在数值上低于纯种。配种年份效应和母本效应显著影响繁殖性能(P<005)。高代杂种在现有生产体系下实现最佳的遗传环境匹配,适宜在北方农区生产体系中推广养殖。

The objective of this investigation was to evaluate the reproductive performance of crossbreds of Holstein cattle, 293 dairy cattlein 3 groups（low-hybrids cow, improved-hybrids cow and pure Holstein cattle） were used. American proved Holstein bull was used to im-prove the different dairy cattle group, according to pedigree to track each group’s descendants. Days Open（DO）, Days to First Breeding（DFB） and Age at First Calving（AFC） data were collected. Least squares method was used to analyze the correlation between group, gen-eration, breeding years, dam, lactation and reproductive performance. The results showed that the DO of low-hybrids and improved-hybridscows was significantly fewer than that of pure Holsteins（P〈0 05）; DFB of low-hybrids cows was significantly fewer than that of pure Hol-stein（P〈0 05）, DFB of improved-hybrids cow to be numerically fewer than pure Holstein. DFB of low-hybrids and improved-hybridscows were significantly fewer than that of pure Holstein at 1 generation（P〈0 05）; AFC of improved-hybrids cows was significantly fewerthan low-hybrids cows at 1 generation（P〈0 05）, AFC of improved-hybrids cows to be numerically fewer than that of pure Holstein cattleat 1 generation. Breeding years and dam had significantly effects on reproductive performance（P〈0 05）. Improved-hybrids cows achievedthe best matching genetic environment under the existing production system, and suitable for the promotion breeding in the northern agricul-tural production system.