无角道塞特羊胚胎移植技术研究

(1)超排处理无角道塞特绵羊163只,育成羊(76只)只均回收胚胎5.53枚,可用胚3.91枚,经产母羊(87只)只均回收胚胎7.55枚,可用胚6.34枚。经产羊平均回收胚胎总数高于育成羊(P<0.05)。春季和秋季之间超排效果差异不明显。重复超排羊和非重复超排羊之间平均回收胚胎总数和可用胚胎数差异均不显著(P>0.05)。(2)共处理受体876只,春季和秋季受体的同期发情率分别为56.37%和89.02%,发情受体利用率分别为84.67%和88.77%。(3)移植受体545只,妊娠318只,产羔396只,受体移植妊娠率为58.35%,移植胚胎成羔率为57.47%,在移植受体中,小尾寒羊的妊娠率最高为61.2%,同羊和内蒙细毛羊分别为54.62%和56.58%,受体品种之间移植妊娠率差异不显著(P>0.05)。受体黄体数对移植妊娠率及胚胎成羔率有一定的影响。胚胎的发育阶段对移植妊娠率也有影响,移植囊胚受体妊娠率最高为64.76%,明显高于早期桑椹胚移植妊娠率42.86%(P<0.05)。胚胎成羔率从桑椹胚到囊胚差异不显著(P>0.05)。

Effect Factors on Embryo Transfer in Poll Dorset Sheep

The study confirmed the effect of donor and recipient and embryo stage etc on sheep embryo transfer. (1)Poll Dorset (n=163) sheep were treated by superovulation (SOV), the number of embryos was evaluated in virgin ewes (n=76) and in ewes-once delivery (n=87), respectively. The mean number of embryo and useful embryo recovery was significantly higher in virgin ewes than in ewes-once delivery (5.33,3.91 versus 7.55,6.34, P<0.05). SOV efficiency was not significantly different in the spring and in the fall, and repeated-SOV had no significant effect on embryo recovery (P>0.05). (2) Estrus synchronization (ES) rate of recipient (n=876) was 56.37% and 89.02% in the spring and in the fall, utility ratio of recipient was 84.67 % and 88.77%, respectively. (3) 318 recipient pregnancy and 396 lambs were born from total 545 recipients transferred, recipient pregnancy and lambing rates were 58.35% and 57.47% respectively. Among all recipients, small-tail sheep had the highest pregnancy rate (61.2%), the second of pregnancy rate were tong sheep (54.62%) and Mongolia fine-wool sheep (56.58%), No significant differences were observed in different sort of recipient (P>0.05), the corpora lutea number of recipient had some side-effect on pregnancy and lambing rate (although not significantly). the embryo stage also contributed to pregnancy rate, recipient of blastocyst transferred got the highest pregnancy rate (64.76%), significantly higher than that of early morula (P<0.05). There was no significant difference in lambing rate per embryo from the morula stage to blastocyst (P>0.05).