Effect of STAT1, OLR1, CSN1S1, CSN1S2 , and DGAT1 genes on milk yield and composition traits of Holstein breed

ABSTRACT The objectives of the study were to evaluate allelic frequencies and test the association between STAT1, OLR1, CSN1S1, CSN1S2 , and DGAT1 gene polymorphisms and milk production traits including lactation milk yield, 305 days milk yield, days before peak milk production, and peak milk yield. In addition, samples of milk were analysed for fat, protein, lactose, and total solid contents. A total of 168 purebred Holstein-Fresian cows were genotyped using polymerase chain reaction and restriction fragment length polymorphism methods. Statistical analysis was carried out using least square methods of the general linear model procedure. Significant differences were found between genotypes of the CSN1S2 locus in relation to milk protein content. In addition, DGAT1 was significantly associated with peak milk production. These results suggested that CSN1S2 and DGAT1 markers may be evaluated to achieve various commercial goals in dairy cattle production.

摘要
本研究旨在评估等位基因频率，并检验信号转导与转录激活因子1（STAT1）、氧化低密度脂蛋白受体1（OLR1）、酪蛋白αS1（CSN1S1）、酪蛋白αS2（CSN1S2）及二酰基甘油酰基转移酶1（DGAT1）的基因多态性与泌乳奶产量、305天奶产量、泌乳高峰前天数、峰值奶产量等奶牛泌乳生产性状的关联。此外，本研究对牛奶样本中的脂肪、蛋白质、乳糖及总固形物含量进行了分析。研究共纳入168头纯种荷斯坦-弗里生奶牛，采用聚合酶链反应（polymerase chain reaction，PCR）与限制性片段长度多态性（restriction fragment length polymorphism，RFLP）方法完成基因分型，统计分析采用一般线性模型程序的最小二乘法。结果显示，CSN1S2位点的不同基因型在乳蛋白含量上存在显著差异；此外，DGAT1与峰值奶产量存在显著关联。上述研究结果表明，可针对CSN1S2与DGAT1分子标记开展评估，以实现奶牛养殖中的各类商业化目标。