Roche J F
Vet Rec. 1977 May 28;100(22):468-70. doi: 10.1136/vr.100.22.468.
The time of ovulation was determined in heifers following two injections 11 days apart of 500 microgram of cloprostenol by recovery of reproductive tracts at slaughter. Ovulation had not begun by 72 hours while 31%, 61% and 95% had ovulated by 78, 92 and 96 hours respectively after the second injection of cloprostenol. Injection of synthetic LH-releasing factor (GnRH) given 48 hours after cloprostenol significantly hastened the time of ovulation in animals slaughtered at 78 hours after the second cloprostenol injection. Insemination of heifers at 48, 60 or 72 hours resulted in lower fertility than two inseminations at 60 and 72 hours or at 48 and 72 hours after treatment. Controlling the time of ovulation with GnRH did not increase the fertility following a single insemination 71 hours after the treatment with cloprostenol.
通过屠宰时回收生殖道来确定小母牛在间隔11天两次注射500微克氯前列醇后的排卵时间。在第二次注射氯前列醇后72小时排卵尚未开始，而分别在78、92和96小时时，31%、61%和95%的小母牛已经排卵。在氯前列醇注射48小时后注射合成促黄体素释放因子（GnRH），显著加快了在第二次氯前列醇注射后78小时屠宰的动物的排卵时间。在48、60或72小时对小母牛进行授精，其受胎率低于在处理后60和72小时或48和72小时进行两次授精的情况。用GnRH控制排卵时间并没有增加在氯前列醇处理71小时后单次授精后的受胎率。
