绵羊同步发情和超数排卵的研究

STUDIES ON SUPEROVULATION AND ESTROUS SYNCKRONIZATION IN THE SHEEP

应用国产激素于发情季节对90只东北细毛羊和半细毛羊进行超数排卵和同步发情,研究了不同激素、不同超排和同步发情方案、不同品种及重复超排对绵羊超排效果的影响。实验结果表明:方法Ⅰ用提纯FSH、PGF_(2α)和hCG与方法Ⅱ用孕酮、PMSG、FSH超排绵羊的排卵数差异不显著(p>0.05),但前者的获卵率明显高于后者的(p<0.05)。比较方法Ⅰ与方法Ⅱ发情26～48小时和66～90小时输卵管冲卵(胚)率说明,用方法Ⅱ超排时,卵(胚)进入子宫的速度明显快于方法Ⅰ;用方法Ⅱ超排时,排卵15个以上与排卵少于15个的绵羊其获卵率差异不显著(p>0.05);间隔2个情期再次超排的绵羊排卵数接近于初次超排绵羊的排卵数,但明显高于间隔、1个情期再次超排绵羊的排卵数;用方法Ⅱ超排的东北细毛羊与半细毛羊的排卵数无明显差异(p>0.05);用孕酮同步处理的绵羊超排后,绝大多数于最后1次注射孕酮后42～51小时开始发情,而经PGF_(2α)处理的超排绵羊发情时间很不集中,从注射PG的后18到42小时之间几乎均匀分布。

90ewds of Chinese Northeast fine and medium fine wool breeds were estrus synchrontzed and superovulated with hormones made in China. and the effects of treatment regimens, animal breeds and repeat treatments on the results of superovulation were studied in the experiment. The results are as follows:The number of ovulations in the ewes superovulated with Regimen Ⅰ (purified FSH+PGF_2α+hCG) was not significantly different from that of the ewes treated with Regimen Ⅲ (progesterone+PMSG+FSH)(11.35±1.515vs. 12.5±0.993. P>0.05). but the recovery rate of the former wan significantly higher than that of the latter, P<0.05). The comparison of the oviduct recovery rates made between Regimen Ⅰ and Ⅱ at26-48 and 66 90 hours after the onset of estrus indicated that the low recovery of Regimen Ⅱ was mainoy due to a speedy transport of the ova down the Fallopian tube into the uterus.The recovery rates of tile ewes with more than 15 ovulations did not differ significantly (P>0.05 )from those of the ewes with less than 15 ovulations. when superovulation was done with Regimen Ⅱ.The ewes superovulated repeatedly at a two-cycle interval preduced an ovulation number similiar to that produced by the ewes treated for the first time (12.227±1.277), but significantly higher than that produced by those treated for the second time following a one-cycle interval(7.741±0.68).There was no remarkable difference(P>0.05)in the ovulation number between the fine and medrum fine breeds when su perovulated with Regimen Ⅱ.Most of the ewes synshronized with progesterone injections began to shrow estrus concentratediy within 42-51 hours after the last injection, while the ewes treated with PGF_2α began estrus scatteredly at a wide range of time from 18 to 42hours after the injection.