Lassoued N, Khaldi G, Cognié Y, Chemineau P, Thimonier J
INRAT, laboratoire de recherches ovines et caprines, Ariana, Tunisie.
Reprod Nutr Dev. 1995;35(4):415-26.
Two experiments were conducted on 30 Barbarine ewes (Exp 1) and 40 local Tunisian goats (Exp 2) in seasonal anoestrus (May). In both experiments, half of the females received 20 mg of progesterone intramuscularly just before male introduction (day 0). Blood samples were taken at 4 h intervals from the time of introduction of the ram, for the determination of the time of the preovulatory LH surge in response to the 'ram effect' (Exp 1) and once a day from days 1 to 8 to determine plasmatic progesterone concentrations (Exp 1, Exp 2). The ovulation rate was determined by coelioscopy at days 4 and 9, and oestrus behaviour was monitored twice daily in each experiment. In the ewe, progesterone delayed the time of the preovulatory LH surge (58.8 +/- 10.1 vs 20.5 +/- 10.7 h, P < 0.001), and suppressed hypofunctional corpora lutea (0/15 vs 7/14, P < 0.001). The induced ovulation rate was not significantly different between control and treated females (1.50 +/- 0.52 vs 1.26 +/- 0.46 respectively). Only 1 female in the control group and 2 in the treated group showed oestrus behaviour at the induced ovulation. Suppression of short cycles by progesterone treatment allowed synchronization of oestrus between days 17 and 20 compared to days 14 and 23 in the control group (P < 0.001). In the goat, all induced ovulations in the control group were followed by a short cycle. In the progesterone-treated group, 3 out of 20 goats developed abnormal induced corpora lutea (P < 0.001). First oestrus occurred between days 1 and 8 in control group and between days 2 and 3 in treated goats. Treatment with progesterone increased the percentage of females showing oestrus at induced ovulation (100 vs 35%, P < 0.001). The ovulation rate at first oestrus was increased in treated goats (1.85 vs 1.35, P < 0.001). In conclusion, 20 mg progesterone administered at day 0 is efficient at preventing the occurrence of short ovarian cycles. After ovulation induced by the male effect, the percentage of females in oestrus, and the induced ovulation rate are increased by progesterone treatment.
在季节性发情间期（5月），对30只巴巴里母羊（实验1）和40只突尼斯本地山羊（实验2）进行了两项实验。在两项实验中，一半的雌性在引入公羊前（第0天）肌肉注射20毫克孕酮。从引入公羊时开始，每隔4小时采集一次血样，以确定对“公羊效应”产生反应的排卵前促黄体生成素激增时间（实验1），并在第1天至第8天每天采集一次血样，以测定血浆孕酮浓度（实验1、实验2）。在第4天和第9天通过腹腔镜检查确定排卵率，并且在每个实验中每天两次监测发情行为。在母羊中，孕酮延迟了排卵前促黄体生成素激增的时间（58.8±10.1小时对20.5±10.7小时，P<0.001），并抑制了功能减退的黄体（0/15对7/14，P<0.001）。对照组和处理组的诱导排卵率无显著差异（分别为1.50±0.52和1.26±0.46）。对照组只有1只雌性和处理组有2只雌性在诱导排卵时表现出发情行为。与对照组第14天至第23天相比，孕酮处理抑制短周期使得发情同步到第17天至第20天（P<0.001）。在山羊中，对照组所有诱导排卵后均出现短周期。在孕酮处理组中，20只山羊中有3只出现异常诱导黄体（P<0.001）。对照组首次发情发生在第1天至第8天，处理组山羊发生在第2天至第3天。孕酮处理增加了在诱导排卵时表现出发情行为的雌性百分比（100%对35%；P<0.001）。处理组山羊首次发情时的排卵率增加（1.85对1.35；P<0.001）。总之,在第0天给予20毫克孕酮可有效防止短卵巢周期的发生,在雄性效应诱导排卵后,孕酮处理可提高发情雌性的百分比和诱导排卵率
