东北细毛羊发情和排卵规律的研究

Observations on Estrus and Ovulation in the ChineseNortheast Fine-wool sheep

本实验系统观察了东北细毛羊的繁殖季节开始时间、发情周期长度、发情持续时间、排卵时间及早期胚胎发育进程等。结果表明：（１）在黑龙江地区大多数（７０．３％）东北细毛羊于７月２１日至８月９日开始发情季节，也即于夏至后１个月至５０ｄ内开始发情；（２）发情周期平均长度１６．６３±０．８４ｄ，８０％的羊为１６～１７ｄ，方差组分估计和Ｆ检验判断，发情周期长度在羊个体间和个体内的差异均不显著；（３）平均发情持续时间３８．３４±１３．７３ｈ，８５％的羊为２４～４８ｈ，方差组分估计和Ｆ检验证明，发情持续时间的个体差异显著且个体间差异显著大于个体内差异；（４）发情开始后２６～３５ｈ排卵；（５）发情５１ｈ胚胎处２．细胞期，６６～７２ｈ处４～６细胞期，７６～８１ｈ处８－细胞期。

In this study,such items as the beginning time of breeding season,lengthof the estrous cycle,estrous behavior and duration,time of ovulation and early develop-ment of embrvos in the Chinese Northeast fine-wool sheep were systematically ob-served. The results were as follows : 1. In the Heilongjiang area,most(70.3%)of theewes of this breed began their sexual season from July 21 to August 9,i.e。 one monthto 50 days after the Summer Solstice,2. The average length of the estrous cycle in thisbreed was 16. 63±0. 84 days and in 80%of the ewes ,the cycle lasted l6- 17 days;AF-value test showed that both the differences between and within individuals were not sig-nificant in the length of the cycle,3. The average duration of estrus was 38. 34±13. 73hours , 85%of the estruses lasted 24-48 hours; results of F-value test indicated that thedifference in estrous duration between individual ewes was significant and surpassed thatwithin the individual.4. The Northeast fine-wool ewes ovulated 26-35 hours after theonset of estrus,5. Embryos recovered 5 1 hours after the onset of heat were at 2-cellstage,and those collected at 66-72 hours and 76-81 hours were at 4 to 6-cell stage and 8-cell stage ,respectively。