智利进口荷斯坦牛β-Lg和β-CN基因多态性及其对泌乳性能的影响

The Influence of β-Lg and β-CN Polymorphism on the Lactation Performances of Holstein Cows Imported from Chile

本研究利用聚丙烯酰胺凝胶电泳(PAGE)对江苏某大型奶牛场智利进口荷斯坦牛β-Lg(β-乳球蛋白)和β-CN(β-酪蛋白)基因多态性进行分型,同时收集采样牛只2016～2018年DHI检测结果,利用最小二乘模型分析其多态性及其对泌乳性能的影响。结果表明,在检测群体中β-Lg有A、B两种等位基因,基因频率分别为0.527和0.473,有AA、AB、BB三种基因型,优势基因型为AB型,频率为0.569;β-CN有A、B两种等位基因,其基因频率分别为0.960和0.040,有AA和AB两种基因型,优势基因型为AA型,频率为0.920。方差分析表明,β-Lg对日产奶量、乳蛋白率、体细胞评分(SCS)和尿素氮含量均有极显著影响(P<0.01);β-CN对乳蛋白率和脂蛋白比有显著影响(P<0.05),对日产奶量影响极显著(P<0.01)。该结果为利用乳蛋白基因多态性提高智利进口荷斯坦牛泌乳性能提供了参考资料。

The β-Lg and β-CN gene polymorphisms were typed by polyacrylamide gel electrophoresis (PAGE) for Chile imported Holstein cows in a large dairy farm of Jiangsu province, and the relationships between milk protein polymorphisms and milk traits were studied by using the least squares method. The results showed that β-Lg was controlled by A and B gene and the frequencies of β-Lg A were 0.527 and β-Lg B were 0.473, there were AA, AB and BB genotypes, the dominant genotype of β-Lg was AB and the frequency was 0.569. β-CN was controlled by A and B gene and the alleles gene frequency was 0.976 and 0.024, respectively, there were AA and AB genotypes, the dominant genotype of β-CN was AA and frequency was 0.920. Variance analysis showed that β-Lg had extremely significant effects on daily milk yield, protein percentage, SCS and urea nitrogen content(P<0.01). β-CN obviously affected protein percentage and fat to protein ratio(P<0.05). Furthermore, β-CN had extremely significant effects on daily milk yield(P<0.01). The results of the use of milk protein polymorphisms could improve lactation performance of Holstein imported from Chile provide references.