Duangjinda M, Buayai D, Pattarajinda V, Phasuk Y, Katawatin S, Vongpralub T, Chaiyotvittayakul A
Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Thailand.
J Anim Sci. 2009 Feb;87(2):469-76. doi: 10.2527/jas.2007-0789. Epub 2008 Sep 26.
Bovine leukocyte antigen DRB3 alleles from Holstein x Zebu crossbred dairy cows (n = 409) were analyzed using the PCR-RFLP technique. Exon II of DRB3 was amplified using locus-specific primers (HLO30/HLO32), followed by digestion with 3 restriction enzymes (RsaI, BstyI, and HaeIII). Forty alleles were found with frequency ranging from 0.005 to 0.139. The most frequently detected alleles of Holstein x Zebu were DRB3*16, *51, *23, *11, *8, and 1, accounting for 61.12% of the alleles in the population. Detection of candidate alleles for clinical mastitis occurrence was performed by logistic regression. It was found that percentage of Holstein fraction in crossbred cows had a nonsignificant effect (P > 0.05). However, parity had a significant effect on mastitis occurrence. In addition, DRB31 and *52 were the most associated with the occurrence of clinical mastitis, whereas *15, *51, and 22 were associated with resistance in crossbred populations. This is the first report of association of DRB315 and 51 with mastitis resistance. The association was validated by examining the candidate alleles in another commercial population. Highly susceptible (n = 43) and resistant (n = 42) groups of Holstein x Zebu cows were investigated. The result confirmed that DRB31 and *52 could be considered as susceptibility alleles, whereas *15, *51, and 22 could be considered as resistant alleles in Holstein x Zebu raised under tropical conditions. In addition, allele effects on 305-d milk production were estimated by BLUP. It was shown that most alleles associated with high clinical mastitis occurrence were related to increased milk yield. This study revealed that allele DRB310 had the greatest effect on increasing milk yield with moderate resistance to clinical mastitis, which could be used as a potential marker for selection in dairy genetic evaluation.
利用聚合酶链反应-限制性片段长度多态性（PCR-RFLP）技术分析了荷斯坦牛与瘤牛杂交奶牛（n = 409）的牛白细胞抗原DRB3等位基因。使用位点特异性引物（HLO30/HLO32）扩增DRB3的外显子II，然后用3种限制性内切酶（RsaI、BstyI和HaeIII）进行酶切。共发现40个等位基因，频率范围为0.005至0.139。荷斯坦牛与瘤牛杂交后代中最常检测到的等位基因是DRB316、51、23、11、8和1，占群体中等位基因的61.12%。通过逻辑回归分析临床乳腺炎发生的候选等位基因。结果发现，杂交奶牛中荷斯坦牛血统的比例影响不显著（P > 0.05）。然而，胎次对乳腺炎的发生有显著影响。此外，DRB31和52与临床乳腺炎的发生最相关，而15、51和22与杂交群体的抗性相关。这是DRB315和51与乳腺炎抗性关联的首次报道。通过在另一个商业群体中检测候选等位基因对该关联进行了验证。对荷斯坦牛与瘤牛杂交奶牛的高易感组（n = 43）和抗性组（n = 42）进行了研究。结果证实，在热带条件下饲养的荷斯坦牛与瘤牛杂交奶牛中，DRB31和52可被视为易感等位基因，而15、51和22可被视为抗性等位基因。此外，通过最佳线性无偏预测（BLUP）估计等位基因对305天产奶量的影响。结果表明，大多数与高临床乳腺炎发生率相关的等位基因与产奶量增加有关。本研究表明，等位基因DRB3*10对提高产奶量的影响最大，同时对临床乳腺炎具有中等抗性，可作为奶牛遗传评估中的潜在选择标记。
