影响牦牛种间杂交受胎率的免疫学因素

Immunological Factors Effecting Conception Pate of Inter species Crossing of Yak with Cattle

普通牛（冻精）与牦牛种间杂交表现的低受胎率不仅与参配母牦牛的质量，饲养管理，冻精品质，输配技术以及某些生殖器官疾患等因素有关，而且涉及免疫学因素，即存在免疫不孕。研究结果表明：黑白花公牛精液经人工授精多次注入母牦牛生殖道内，能使母耗牛机体产生精子免疫应答；精子抗原存在于精子的头部和尾部；精子免疫以体液免疫反应为主，精子抗体的产生致精子再次进入生殖道时知活甚至凝集，使精子难以上行和受精。

The low conception rate of interspecies crossing of yak with cattle is not only affected by the factors such as the quality of yak famles,nutrition and management,quality of frozen semen,techniques of inseminators and reproductive organ disease,but also relates to immunological factors i.e.immunological infertility,The study result shows that yak females produce sperm antibodies ifthey have received severaltim esofHolstein sem en insem ination. Sperm antigen is located in the head and the tailofthe sperm .Sperm im m unization is dom i- nated by hum oralim m unity. The occurrence of sperm s in the genitaltract,thus disrupting norm alsperm transport and fertilization i.e.low er conception rate ofinterspecies crossing in the yak.The num ber ofyak fem ales w ith positive rate ofsperm antibodies is 26.79% in the served yak fem ales,and this accounts for 42.61% ofthose non-pregnant.