摘要
Laparoscopic insemination with frozen-thawed semen is currently used for planned matings in the Sarda breeding programme. In order to find a fast and less intrusive artificial insemination (AI) method that could replace laparoscopic insemination, a field comparison of laparoscopic and transcervical techniques was carried out on 200 mature Sarda ewes. After AI, ewes were assigned to teaser and fertile rams for 2 months. Return rates and cumulative (AI + natural mating) lambing rates were recorded over three subsequent 23-day periods. Lambing rates to AI were significantly different (P < 0·01), and were 62% and 7% respectively for laparoscopic and transcervical AI. Cumulative lambing rates after two further 23-day periods of natural mating were no longer significantly different (P > 0·05) and reached 82% and 74% respectively. Ewes with body condition scores at AI higher than 2·75 showed better overall reproductive performance, but not higher pregnancy rate to AI. Plasma cortisol concentrations, sampled twice, before and after AI, were higher (P < 0·01) in the last sample, suggesting a stress response to insemination. Cortisol levels after AI were lower (P < 0·01) for ewes submitted to transcervical rather than laparoscopic insemination (P < 0·01). However, cortisol levels after AI were no greater than those recorded when ewes were restrained in a milking yoke different from that usually employed. Laparoscopic AI was confirmed as the most suitable technique for insemination offrozen semen in the Sarda breeding scheme.
摘要译文
目前，在Sarda育种计划中，腹腔镜授精与冷冻 - 解冻精液一起用于计划交配。为了找到可以取代腹腔镜授精的快速且侵入性较小的人工授精（AI）方法，对200只成熟的Sarda母羊进行了腹腔镜和经宫颈技术的现场比较。在AI之后，母羊被分配到预告片和肥沃的公羊2个月。在随后的三个23天期间记录回报率和累积（AI +自然交配）产羔率。 AI的羔羊率显着不同（P <0.01），腹腔镜和经宫颈AI的羔羊率分别为62％和7％。经过两次23天的自然交配后，累积产羔率不再有显着差异（P> 0.05），分别达到82％和74％。身体状况评分为AI高于2·75的母羊表现出更好的整体繁殖性能，但对AI的妊娠率不高。在AI之前和之后采样两次的血浆皮质醇浓度在最后一个样本中较高（P <0.01），表明对授精的应激反应。对于接受经宫颈镜检查而非腹腔镜人工授精的母羊，AI后皮质醇水平较低（P <0.01）（P <0.01）。然而，AI后的皮质醇水平不大于当母羊被限制在不同于通常使用的挤奶轭时记录的那些水平。在Sarda育种计划中，腹腔镜AI被确认为最适合授精离体精液的技术。
P. Cappai (a1); S. R. Sanna (a1); A. Branca (a1); A. Fraghì (a1);G. Bomboi (a2).... Comparison of laparoscopic and transcervical insemination with frozen semen in Sarda dairy ewes[J]. Animal Science, 1998,66(2): 369-373