中文摘要：

为了解子宫颈粘液对奶牛后代性别影响，采集200头奶牛的子宫颈粘液，测定子宫颈粘液的pH值并记录与其相应编号的母牛后代性别用以推测宫颈粘液pH值与后代性别的相关性。实验结果显示子宫颈粘液的pH值越高后代为雄性的几率越大，反之宫颈粘液pH值越低产雌性个体的几率越大。奶牛子宫颈粘液phi〈6.7的母牛，后代性别多为雌性，pH值≥7.6时，后代多为雄性，奶牛子宫颈粘液pH值在6.8～7.5之间时，雌雄后代数目较为均等，接近于1：1。

英文摘要：

To investigate the influence of cervical mucus pH on cow offspring sex. By collect cervical mucus from 200 cows, survey pH value of cervical mucus and record the number of cows and their offspring gender to speculate the relationship between cervical mucus pH value and gender of offspring. The results shows as the cervical mucus pH is higher the rate of male offspring is higher, on the contrary, the pH is lower the rate of female offspring is higher. When the cervical mucus pH≤6.7,offspring gender is mostly female, when pH≥7.6,offspring gender is mostly male, when the cervical mucus pH between 6.8-7.5, the number of male and female offspring is close to 1：1.