Investigation of oocyte maturation and fertilizati in high-producing and sub-fertile dairy cows

为了阐明现代高产奶牛受精率低的原因，我们调查了现代高产奶牛卵母细胞成熟和受精的特点。结果揭示了黄体生成素高峰后的排卵时间和体内成熟的排卵前卵母细胞的超微结构。估计精子进入输卵管储存库所需的时间和排卵卵母细胞的功能寿命。通过使用体外成熟的卵母细胞，我们定义了发育能力获得的特征。此外，我们开发了一种利用精浆蛋白处理重复繁殖奶牛的新方法，以及一种新的卵母细胞体外生长培养系统，以检测应激对卵母细胞生长和成熟的影响。并指出通过监测阴道温度变化来预测排卵和排卵异常的时间。

To elucidate the causes of low fertility in modern high producing dairy cows, we investigated the characteristics of oocyte maturation and fertilization. As the results, the time of ovulation after LH surge and the ultrastructure of in vivo matured preovulatory oocytes were revealed. The time required for the sperm transport to the oviduct reservoir and functional life span of ovulated oocytes were estimated. By using in vitro mature oocytes, we defined the characters of acquisition of developmental capacity. Moreover, we developed a novel treatment of repeat breeding cows by using seminal plasma proteins, and a new in-vitro oocyte growth culture system to examine the effects of stresses on oocyte growth and maturation. The possibility of prediction of the time of ovulation and abnormal ovulation by monitoring vaginal temperature changes was also indicated