Investigation for effects of blood coagulation factor XI deficiency on productivity to the genetic improvement of Japanese beef cattle

血液凝固因子Xi缺乏症是在日本黑牛中观察到的一种遗传性疾病。虽然这种疾病的临床状况是温和的，但由于日本黑牛群体中突变等位基因的等位基因频率非常高，因此认为这种疾病的经济影响是严重的。因此，我们调查的影响因素Xi缺乏缺陷的怀孕和分娩和胴体性状使用大样本的日本黑牛。结果发现，因子Xi缺乏的受影响动物具有流产和死胎频率增加的趋势，但对小牛的状况和胴体性状没有影响。这些研究结果将有助于日本黑牛的育种。

Blood coagulation factor XI deficiency is a hereditary disorder observed in Japanese Black cattle. While the clinical condition of this disorder is mild, the economical impact of this disorder is apprehended to be serious because of the remarkably high allelic frequency of the mutant allele in the population of Japanese Black cattle. We, therefore, investigated the effect of the factor XI deficiency on defects in pregnancy and delivery and carcass traits using large samples of Japanese Black cattle. As a result, we found that affected animals of factor XI deficiency have a tendencies for increased frequencies of abortion and stillborn, but no effect on the condition of calf and carcass traits. These findings will be useful to future breeding of Japanese Black cattle.