【摘要】 通过PCR-RFLP的方法,分析催乳素基因exon3在543头北京荷斯坦母牛中的多态性,得到3种基因型:AA、AB和BB,基因型频率分别为0.734,0.257,0.009,并对不同基因型间产奶性能进行了最小二乘法拟合线性模型分析。结果表明:在泌乳Ⅰ期,AA和AB基因型奶牛的奶、乳脂和乳蛋白产量高于BB基因型(P<0.01),在泌乳Ⅱ期,AB基因型奶牛的的奶、乳脂和乳蛋白产量高于AA基因型(P<0.01);在泌乳Ⅱ和Ⅲ期,AA基因型奶牛的乳蛋白率高于AB基因型(P<0.05)。更多还原

【Abstract】 PCR-RFLP method was used for identification of genotypes.The following frequencies of genotypes were found: 0.734,0.257 and 0.009 for AA,AB and BB,respectively.Associations were analysed between polymorphisms localized in exon 3 of the prolactin gene and milk production traits of Beijing Holstein cows,including a total of 543 cows.The results of the least squares means show: both AA and AB cows are of higher milk yield,milk fat yield and milk protein yield than BB individuals in lactation Ⅰ.AB cows are of higher milk yield,milk fat yield and milk protein yield than AA cows in lactation Ⅱ(P<0.01).AA cows produced milk with higher protein content than AB individuals in lactation Ⅱ and Ⅲ(P<0.05).更多还原