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

凝血因子XI缺乏症是日本黑牛的一种遗传性疾病。虽然这种疾病的临床症状是轻微的，但这种疾病的经济影响被认为是严重的，因为日本黑牛种群中突变等位基因的等位基因频率非常高。因此，我们利用大量日本黑牛样本研究了因子XI缺乏对妊娠和分娩缺陷以及胴体性状的影响。结果发现，因子XI缺乏的病畜有流产和死产的趋势，但对犊牛状况和胴体性状没有影响。这些发现对今后日本黑牛的选育具有一定的参考价值。

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.