Husein M Q, Ababneh M M
Department of Animal Production, Faculty of Agriculture, P.O. Box 3030, Jordan University of Science and Technology, Irbid 22110, Jordan.
Theriogenology. 2008 Feb;69(3):376-83. doi: 10.1016/j.theriogenology.2007.10.005. Epub 2007 Nov 26.
Two experiments were conducted to examine the effect of progestagen supplement 24h prior to intravaginal pessary withdrawal on reproductive performance of seasonal anestrous ewes. Ewes in each experiment were allocated to treatment and control and all were induced to estrus using either intravaginal MAP (Exp. 1; n=24) or CIDR-G (Exp. 2; n=28) pessaries for 12 days. Half of the ewes in each experiment were supplemented 24h before withdrawal of pessaries with either 10mg oral MAP tablets (Exp. 1) or 25mg i.m. progesterone (P(4)) administration (Exp. 2; P(4)-supplement-treated group). Fertile rams were allowed with the ewes at sponge removal (Day 0, 0h) and estrus was monitored at 6-h intervals for 3 days. Blood samples were collected for measurements of P(4) (Exp. 1 and Exp. 2) and LH (Exp. 2). In both experiments, the percent of ewes in estrus was greater (P<0.05) and intervals to estrus were longer (P<0.05) in progestagen-supplement-treated than control ewes. In Exp. 2, the occurrence and magnitude of LH surges were greater (P<0.01) and intervals to onset of LH surge were longer (P<0.01) in P(4)-supplement-treated than control ewes. In Exp. 2, P(4) supplement elevated P(4) levels from 1.8+/-0.1ng/mL on Day -1 to 4.2+/-0.3 on Day 0 (P<0.001). Following pessaries removal, P(4) concentrations fell to basal values on Day 1 in both groups and remained low until Day 5. Then, P(4) concentrations increased and remained elevated through Day 19 in all (100%) progestagen-supplement-treated in Exp. 1 (12/12) and Exp. 2 (14/14) and in only 5/12 (41.7%) and 6/14 (42.9%) control ewes, respectively. These ewes were confirmed pregnant by ultrasonography and lambed on Day 149.2+/-0.2 following Day 0. In conclusion, progestagen supplement 24h prior to removal of pessary can be used successfully to improve reproductive performance of ewes bred out-of-season.
进行了两项实验，以研究在取出阴道内子宫托前24小时补充孕激素对季节性发情母羊繁殖性能的影响。在每个实验中，母羊被分为处理组和对照组，所有母羊均使用阴道内埋植醋酸甲地孕酮（实验1；n = 24）或孕酮释放阴道环（CIDR-G，实验2；n = 28）诱导发情12天。在每个实验中，一半的母羊在取出子宫托前24小时补充10mg口服醋酸甲地孕酮片（实验1）或25mg肌肉注射孕酮（P(4)）（实验2；P(4)补充处理组）。在取出阴道海绵栓时（第0天，0小时），将可育公羊放入母羊群中，并每隔6小时监测发情情况，持续3天。采集血样用于检测P(4)（实验1和实验2）和促黄体生成素（LH，实验2）。在两个实验中，补充孕激素处理的母羊发情百分比更高（P<0.05），发情间隔更长（P<0.05）。在实验2中，P(4)补充处理的母羊促黄体生成素高峰的发生率和幅度更高（P<0.01），促黄体生成素高峰开始的间隔更长（P<0.01）。在实验2中，P(4)补充使P(4)水平从第-1天的1.8±0.1ng/mL升高到第0天的4.2±0.3ng/mL（P<0.001）。取出子宫托后，两组母羊的P(4)浓度在第1天降至基础值，并一直保持低水平直到第5天。然后，P(4)浓度升高，并在实验1（12/12）和实验2（14/14）中所有（100%）补充孕激素处理的母羊中持续升高至第19天，而对照组母羊中分别只有5/12（41.7%）和6/14（42.9%）出现这种情况。这些母羊经超声检查确认怀孕，并在第0天后的第149.2±0.2天产羔。总之，在取出子宫托前24小时补充孕激素可成功用于提高非繁殖季节配种母羊的繁殖性能。
