This study assessed the effect of progestogen treatment length on ovarian parameters and embryo yield in superovulated Lacaune ewes collected by nonsurgical embryo recovery. Twenty-three lactating ewes were superovulated 30 d apart using a cross-over design. All ewes received 60 mg of MAP intravaginal sponges for 6 (G-6 group) or 9 (G-9 group) d. A total dose of 133 mg pFSH was given in six decreasing doses (twice a day) starting at 60 h before device removal. Ultrasound examination of the ovaries was performed at the first pFSH injection and one day before embryo recovery, which was performed 6-7 d after the onset of estrus. Embryo recovery was conducted only in ewes that expressed estrus and were mated. There was no difference (P > 0.05) in the total number of follicles between G-6 (15.7 ± 1.0) and G-9 (15.6 ± 0.8) at the time of the first pFSH treatment. The percentage of responding donors with ≥3 corpora lutea (CL; 78.2% [18/23] vs 69.5% [16/23]), mean (±SEM) CL number (7.0 ± 1.2 vs 8.1 ± 1.6), transcervical passage rate (94.4% [17/18] vs 83.3% [15/18], and ova/embryo recovery rate (54.5% [60/110] vs 68.0% [83/122]) were not different (P > 0.05) between the G-6 and G-9 groups. However, the mean number of viable embryos was lower (P < 0.05) in the G-6 group (1.8 ± 0.7) than in the G-9 group. (3.5 ± 1.1). In conclusion, treatment with an intravaginal MAP sponge for 9 d during a superovulation protocol is beneficial for viable embryo yield in Lacaune ewes out of the breeding season.

中文翻译：

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哺乳期拉卡恩母羊超排卵方案中胚胎产量和质量与孕激素治疗相关

本研究评估了孕激素治疗长度对通过非手术胚胎恢复收集的超排卵拉卡恩母羊卵巢参数和胚胎产量的影响。23 只泌乳母羊使用交叉设计相隔 30 天超量排卵。所有母羊接受 60 mg MAP 阴道海绵 6 (G-6 组) 或 9 (G-9 组) d。从装置移除前 60 小时开始，以六次递减剂量（每天两次）给予总剂量 133 mg pFSH。在第一次 pFSH 注射和胚胎恢复前一天进行卵巢的超声检查，在发情后 6-7 天进行。仅在表达发情并已交配的母羊中进行胚胎恢复。G-6 (15.7 ± 1.0) 和 G-9 (15.6 ± 0) 的卵泡总数没有差异 (P > 0.05)。8) 在第一次 pFSH 治疗时。有≥3个黄体的响应供体百分比（CL；78.2% [18/23] vs 69.5% [16/23]），平均（±SEM）CL数（7.0 ± 1.2 vs 8.1 ± 1.6），经宫颈通过率（94.4% [17/18] vs 83.3% [15/18]，卵子/胚胎恢复率（54.5% [60/110] vs 68.0% [83/122]）在两组之间没有差异（P > 0.05） G-6 和 G-9 组。然而，G-6 组 (1.8 ± 0.7) 的平均存活胚胎数 (P < 0.05) 低于 G-9 组 (3.5 ± 1.1)。结论是，在超排卵方案期间用阴道内 MAP 海绵处理 9 天有利于拉考恩母羊在繁殖季节外的存活胚胎产量。