In the present study, there was evaluation of the alternative of adding eCG as part of a long-interval prostaglandin-F_2α (PG) treatment on the reproductive efficiency of Merino sheep during the breeding season. A total of 210 ewes and 182 ewe lambs were randomly assigned to three experimental groups to induce the timing of estrus among ewes in a: Long-interval PG, group being synchronized using two doses of PG 14 days apart; Long-interval PG + eCG group being synchronized using the same treatment regimen as Group PG with the addition of 200 IU eCG to the regimen, administered concomitantly with the second PG administration; and MAP + eCG group being synchronized with intravaginal progestin sponges for 14 days plus 200 IU eCG, administered at the time of sponge removal. The percentage pregnancy rate in ewes of the MAP + eCG group was greater than the ewes of the Long-interval PG and Long-interval PG + eCG groups (76.4 % compared with 52.0 % and 62.5 %, respectively; P < 0.05). The prolificacy rate was greater in the ewes of the Long-interval PG+eCG group compared with the other groups (114 % compared with 100 % and 103 %, respectively; P < 0.05). When considering the fecundity rate, ewes of the Long-interval PG+eCG and MAP+eCG groups had greater values than ewes of the Long-interval PG group (71.2 % and 78.8 % compared with 52.0 %, respectively; P < 0.05). The Long-interval PG+eCG is an alternative to the conventional progestin sponge plus eCG treatment regimen with there being a greater fecundity rate when this regimen is used compared with the Long-term PG and similar to MAP-eCG treatment regimens.

在本研究中，评估了添加 eCG 作为长间隔前列腺素 F _{2α 的}一部分的替代方案(PG) 在繁殖季节对美利奴羊繁殖效率的处理。总共210只母羊和182只母羊羔被随机分配到三个实验组中以诱导母羊发情的时间：长间隔PG，组使用间隔14天的两剂PG同步；长间隔 PG + eCG 组同步使用与 PG 组相同的治疗方案，并在该方案中加入 200 IU eCG，与第二次 PG 给药同时给药；和 MAP + eCG 组与阴道内孕激素海绵同步 14 天，外加 200 IU eCG，在海绵移除时给药。MAP + eCG 组母羊的妊娠率高于 Long-interval PG 和 Long-interval PG + eCG 组的母羊（分别为 76.4 % 与 52.0 % 和 62.5 %；P  < 0.05)。与其他组相比，长间隔 PG+eCG 组的母羊的繁殖率更高（分别为 114 % 与 100 % 和 103 %；P  < 0.05）。在考虑繁殖率时，长间隔PG+eCG和MAP+eCG组的母羊比长间隔PG组的母羊具有更高的值（分别为71.2 %和78.8 %对52.0 %；P  < 0.05）。Long-interval PG+eCG 是传统孕激素海绵加eCG 治疗方案的替代方案，与Long-term PG 相比，该方案具有更高的生育率，并且与MAP-eCG 治疗方案相似。