二酰甘油酰基转移酶(DGAT1)基因K232A位点是一个与奶牛产奶性能有关的重要位点.本研究通过对三河牛K232A位点检测发现,该位点在三河牛中处于Hardy-Weinberg平衡状态,说明没有经过选择.KK基因型个体具有最低的体细胞评分和最高的乳脂率;KA基因型个体具有最高的产奶量和乳脂量;AA基因型个体具有最高的乳蛋白量.K等位基因有利于提高乳脂率和乳脂量,同时降低体细胞评分.在三河牛群体中,K等位基因的基因频率为0.23,利用K位点来提高乳脂率和乳脂量以及降低体细胞评分,存在很大的选择空间.

【Objective】The aim of this study is to detect Y367C site in ATP-binding cassette super-family G member 2(ABCG2) gene in Sanhe cattle and analyze its association with milk production traits.【Method】The detection of the site was analyzed with Sequenom Mass ARRAY Genotype technology.The association between the site and 6 milk production traits was analyzed with software SAS(version 9.1).【Result】The results showed that Y367C conformed to Hardy-Weinberg Law(P0.05).Individuals with YY genotype of Y367C site had the lowest somatic cell score;while those with CC genotype had the highest milk yield,fat yield,and protein yield.Allele Y could improve somatic cell score and protein percentage.Allele C could improve milk yield,fat percentage,fat yield and protein yield,but there was no significant difference among three genotypes(P0.05).【Conclusion】The site could provide reference for molecular breeding in Sanhe cattle.

隐性乳房炎患牛与健康牛外观无异,不易判断,对奶牛业造成的损失严重.金黄色葡萄球菌是引起隐性乳房炎的重要病原菌,准确判断金黄色葡萄球菌型隐性乳房炎是预防和控制乳房炎的重要途径.目前国际上普遍采用乳中体细胞数(SCC)作为检测隐性乳房炎的主要指标,但是约40％的金黄色葡萄球菌型乳房炎牛乳汁中SCC低于20万/mL.笔者依据相邻两月SCC差值高低,采集两个奶牛场荷斯坦牛生产群第一胎泌乳牛奶样65头份,从中检出有6头份含金黄色葡萄球菌.用PCR方法扩增金黄色葡萄球菌和耐甲氧西林金黄色葡萄球菌(MRSA)的特异基因nuc和mecA,结果发现,nuc基因检出率为100％(12/12),未检测到mecA基因.进一步用多重PCR方法检测金黄色葡萄球菌各种毒素基因,其中PVL基因在高SCC与低SCC奶样中的检出率分别为33.3％和100％,差异显著,这可能与PVL破坏白细胞有关.PFGE分型结果表明,所检测到的金黄色葡萄球菌可分为4个簇、5种类型,其中P2型(PVL)为流行株.结果提示,在荷斯坦牛生产群中,如果奶牛产奶量有所下降而SCC也不高时,应辅以分子检测手段来判断是否患有金黄色葡萄球菌型隐性乳房炎.

Data processing plays an indispensable and important role in statistic analysis.It is the basis of quantitative analysis and basic premise of scientific researching in animal breeding and genetic.This paper will detailedly introduce the data processing method from programming with SAS system combined with frequently asked questions in practical work on the analysis of genetic effect of livestock traits.