School of Animal Production Technology, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima, Thailand.
Anim Sci J. 2011 Aug;82(4):512-6. doi: 10.1111/j.1740-0929.2011.00879.x. Epub 2011 Apr 20.
The objective of this study was to compare the genotype, and composite genotype frequency, and the association between beta and kappa casein genes and milk yield (MY), percentage of fat (%Fat), protein (%Prot), and solids non-fat (%SNF) between two groups of crossbred Holstein: G1 ≤ 87.5% Holstein = 89 cows and G2 > 87.5% Holstein = 142 cows. Five genotypes of beta casein gene were observed. A1A2 and A1B were the most and rarest frequency, respectively, in both groups. Five genotypes of kappa casein gene were found. The highest and the lowest frequency were AA, and BB and BE, respectively, in both groups. Composite genotype A1A2AA was the most frequent in both groups. Linkage disequilibrium (LD) between two genes was detected. Significant differences of frequencies between both groups of both genes were not found. The association of the genes and the traits was different between G1 and G2. Negative effects on the traits were found in both groups. In addition, the stronger effect of the beta casein gene was observed in most of the traits. The conclusions were that different %Holstein caused different significant effects of these genes. A study of the association of these genes within each percentage of Holstein is strongly recommended.
本研究的目的是比较两组杂交荷斯坦奶牛（G1≤87.5%荷斯坦=89 头和 G2＞87.5%荷斯坦=142 头）β和κ酪蛋白基因的基因型、复合基因型频率以及与产奶量（MY）、脂肪百分比（%Fat）、蛋白质百分比（%Prot）和非脂固体百分比（%SNF）的关联。观察到β酪蛋白基因的五种基因型。A1A2 和 A1B 是两组中最常见和最罕见的频率。发现κ酪蛋白基因有五种基因型。AA 在两组中的频率最高，BB 和 BE 最低。A1A2AA 复合基因型在两组中最常见。检测到两个基因之间的连锁不平衡（LD）。两组两个基因的频率均无显著差异。两组基因与性状的关联不同。两组都发现了对性状的负影响。此外，β酪蛋白基因对大多数性状的影响更强。结论是不同的荷斯坦百分比导致这些基因产生不同的显著影响。强烈建议对每个荷斯坦百分比的这些基因进行关联研究。
