Tjondronegoro S, Williamson P, Sawyer G J, Atkinson S
School of Veterinary Studies, Murdoch University, Western Australia.
J Dairy Sci. 1987 Oct;70(10):2162-7. doi: 10.3168/jds.S0022-0302(87)80269-2.
Effects of two intravaginal treatments of progesterone on the synchronization of behavioral estrus were compared in three groups of lactating dairy cows at 7 to 8 wk postpartum. Group 1 had progesterone-releasing intravaginal devices with attached estradiol benzoate capsules inserted for 12 d. Groups 2 and 3 had controlled internal drug release devices, containing progesterone alone, inserted for 9 or 12 d. Behavioral estrus was detected as early as 24, 32, and 36 h after removal of the devices in groups 1, 2, and 3, respectively. Estrus was better synchronized and the proportion of cows showing estrus after device removal was greater in group 1 than in groups 2 and 3. After removal of devices, mean milk progesterone of all cows that did not show estrus was higher than that of cows that showed estrus. In groups 1, 2, and 3, 1 of 7, 7 of 12, and 4 of 12 cows not showing estrus had high milk progesterone after removal of the devices, indicating the presence of functional corpora lutea. In cows not displaying estrus milk progesterone concentrations decreased, indicating these cows were cyclic, although behavioral estrus was absent.
在产后7至8周的三组泌乳奶牛中，比较了两种阴道内孕酮处理对行为发情同步化的影响。第1组插入带有苯甲酸雌二醇胶囊的孕酮释放阴道装置12天。第2组和第3组插入仅含孕酮的控释内给药装置9天或12天。分别在第1、2和3组取出装置后24、32和36小时最早检测到行为发情。第1组发情同步性更好，取出装置后表现出发情的奶牛比例高于第2组和第3组。取出装置后，所有未发情奶牛的平均乳孕酮高于发情奶牛。在第1、2和3组中，取出装置后未发情的7头奶牛中有1头、12头奶牛中有7头以及12头奶牛中有4头乳孕酮较高，表明存在功能性黄体。在未表现出发情的奶牛中，乳孕酮浓度下降，表明这些奶牛处于发情周期，尽管没有行为发情。
