连续重复超数排卵、冲胚对引进品种肉羊快速扩繁的效果研究

[目的] 评价引进品种肉羊的连续重复超数排卵（超排）、冲胚、胚胎移植等繁育技术集成模式的应用效果。[方法] 于2016—2018年,对选取的1 575只澳洲白（n=230）、白头杜泊（n=228）、黑头杜泊（n=541）、白头萨福克（n=200）、黑头萨福克（n=376）5个品种母羊,进行间隔30 d以上的连续同期发情（孕酮海绵栓）与超排（330~450 IU FSH+200~300 IU PMSG+0.1 mg PG）处理;经过腹腔内窥镜输精后进行子宫角冲胚,回收胚胎后计数并评估质量,挑取部分胚胎进行移植;对比分析品种、季节、重复超排次数等对胚胎生产指标的影响。[结果] 共获得18 496枚胚胎,有14 971枚可用胚;胚胎移植后的受胎率为69.8%,产羔率为93.2%;只均总胚数和只均可用胚数2项指标显示,胚胎生产特性以白头萨福克、黑头萨福克、黑头杜泊较好,澳洲白次之,白头杜泊最差;不同品种母羊连续重复超排冲胚后回收的只均总胚数和只均可用胚数持续增长,直到第4或第5次;澳洲白的超排冲胚效果在春季较好,而其他品种在冬季较好。[结论] 连续重复超数排卵、冲胚技术对于扩繁引进肉羊品种群体是可行的,应根据不同品种及其表现出的季节特性科学、适时应用。

Effects of Continual and Repeated Superovulation and Embryo Collection on Rapid Propagation of Mutton Sheep of Imported Breeds

[Objective] To assess the applicability of an integrated mode of breeding technologies in mutton sheep of imported breeds, such as continual and repeated superovulation, embryo flushing, and embryo transplantation. [Method] From the year of 2016 to 2018, a total of 1 575 imported mutton ewes belonging to five breeds, including Australian White （n = 230）, White Dorper （n=228）, Dorper （n=541）, White Suffolk （n=200） and Suffolk （n=376）, were treated by continual estrus synchronization （progesterone sponge） and superovulation （330-450 IU FSH + 200-300 IU PMSG + 0.1 mg PG） with an interval of more than 30 days. Intraperitoneal endoscopic insemination was performed to flush out embryos from uterine horn of the ewes. The obtained embryos were counted, evaluated in terms of quality, and then partially transplanted into the synchronized receptors. The impacts of breed, season, and number of repeated superovulation times on embryo productivity were compared and analyzed. [Result] A total of 18 496 embryos were obtained, with 14 971 transferable ones. Gestation rate after embryo transplantation was 69.8% and the lambing rate was 93.2%. According to the mean numbers of recovered total embryos and transferable embryos per ewe, the embryo productivity of White Suffolk, Suffolk and Dorper was superior to Australian White, and White Dorper had the worst performance. After continual and repeated superovulation as well as embryo collection, the mean numbers of recovered total embryos and transferable embryos per ewe of different breeds continued to increase until the 4^th or 5^th treatment. The outcome of superovulation and embryo collection of Australian White was better in spring, while the other breeds were better in winter. [Conclusion] Continual and repeated superovulation as well as embryo collection are feasible breeding technologies for propagation of the mutton sheep of imported breeds. They should be used in a scientific and timely manner, taking into account the various breeds and their seasonal reproductive features.