豫西脂尾羊排卵规律及胚胎生长发育规律的研究

Studies on the Law for Ovulation and Embryo Development in Yuxi Short Thick Dock Sheep

豫西脂尾羊以单侧卵巢排卵为主，单侧卵巢排卵母羊百分比为98．18％，其中左侧为34．35％，右侧为63．64％。右侧卵巢排卵母羊数极显著多于左侧卵巢排卵的母羊数（P＜0．01）。总排卵率及排单卵、双卵和三卵的百分率分别为110．91％、90．91％、7．27％和1．82％。其胚胎长度增长以胎儿中期生长速度最快，而体重增长自进入胎儿中期以后一直比较旺盛。研究结果表明，豫西脂尾羊产羔率低的直接原因是排卵率低，主要是排双卵和三卵的比例低。根据豫西脂尾羊排卵及胚胎生长发育特点，就如何提高其繁殖率问题提出了具体建议和措施。

The ovulation from single ovary is in the majority in Yuxi short thick dock sheep,the percentage of the sheep with ovulation from either ovary is 98. 18 %, including 34. 55 % in left and 63. 64% in right. The obvious difference for the ovulation rate exists between left and right ovary (P<0.01 ). The total ovulation rate is 110. 91 %, the percentage of one-egg,twin-egg and three-egg is 90. 91 %, 7. 27 % and 1. 82 %, respectively. The rapid increasc phase in embryo length is medium-period in course of fetus development,while,the inrease in embryo weight is always strong from fetus medium-period to biith date. This study reveal that the reason for the low lambing percetage is a still lower rate for twin-egg and three-egg. According to the character of the ovulation and embryo development in Yuxi Short Thick Dock Sheep,several specific proposals and measures for increasing the sheep fertility have been put forward.