There was investigation of whether there were ovulations from co-dominant follicles following eCG administration. In all experiments, there was GnRH injection and CIDR insertion on day 0 (D0), CIDR withdrawal on D8, and cloprostenol administration on D8 (Exp. I and II) or D7 and D8 (Exp. III). Females in the control group were not administered any further treatment. Females in other group(s) were treated with eCG (500 IU) on Day 2 in Exp. I, Day 2 (eCG-2) or 8 (eCG-8) in Exp. II and Day 2 (eCG-2) or Days 2 and 6 (eCG-2-6) in Exp. III. Ovaries were examined using ultrasonography. In Experiments I and II, females had follicle emergence on Day 2. At the time of CIDR removal, more eCG-treated heifers (8/9; Exp. I) and cows (5/6; eCG-2; Exp. II) had co-dominant follicles compared to those in the control group (P < 0.05). Occurrence of ovulations from co-dominant for individual cows was minimal. In Experiment III, the time period from CIDR removal to estrus in cows treated with eCG-2 (68 ± 13 h) was longer compared to cows in the control (37±2 h) and eCG-2-6-treated group (38 ± 5 h; P < 0.05). There was a greater proportion of heifers having ovulations and thus greater progesterone concentration in the eCG-2-6 than eCG-2 group (P < 0.05). Administering eCG twice 4 days apart with the initial administration being two days after GnRH administration, at the time of follicle wave emergence, could induce growth of and ovulation from co-dominant follicles and enhance progesterone production in cattle.

研究了 ECG 给药后是否有来自共显性卵泡的排卵。在所有实验中，第 0 天（D0）注射 GnRH 和 CIDR，第 8 天停用 CIDR，第 8 天（实验 I 和 II）或第 7 天和第 8 天（实验 III）使用氯前列醇。对照组中的女性没有接受任何进一步的治疗。其他组中的女性在实验的第 2 天接受 eCG (500 IU) 治疗。I，实验中的第 2 天（eCG-2）或第 8 天（eCG-8）。实验中的第 2 天和第 2 天 (eCG-2) 或第 2 天和第 6 天 (eCG-2-6)。三、使用超声检查卵巢。在实验 I 和 II 中，雌性在第 2 天出现卵泡。在去除 CIDR 时，更多 eCG 处理的小母牛（8/9；实验 I）和奶牛（5/6；eCG-2；实验 II）与对照组相比，具有共显性卵泡（P < 0.05)。个别奶牛共显性排卵的发生率极低。在实验三中，与对照组（37±2 h）和 eCG-2-6 治疗组（38 ± 5 小时；P  < 0.05)。与 eCG-2 组相比，eCG-2-6 组中有更大比例的小母牛排卵，因此黄体酮浓度更高（P  < 0.05）。在卵泡波出现时，间隔 4 天施用两次 eCG，首次施用是在 GnRH 施用后两天，可诱导共显性卵泡的生长和排卵，并增强牛的孕酮产生。