褪黑素对羊精液冷冻后精子运动能力和产羔率的影响

Effects of melatonin on motility of frozen semen and lambing rate in sheep

为了探究褪黑素(melatonin,MT)对冷冻精液解冻后运动能力、妊娠率和产羔性能的影响,试验选取湖羊精液,在冷冻液中添加褪黑素1×10^(-7)mol/L(1组)、1×10^(-5)mol/L(2组)、1×10^(-3)mol/L(3组),对照组不添加褪黑素,对4个组精液进行冷冻,测定了各组解冻前后精子运动能力;采用各组冻后精子对母羊进行人工授精,测定妊娠率和产羔性能。结果表明:湖羊精液冷冻前活力、平均曲线运动速度(VCL)、平均直线运动速度(VSL)、平均路径运动速度(VAP)、精子平均侧摆幅值(ALH)和直线运动精子活率均显著高于冻后各组(P<0.05);冷冻解冻后1组精子活力显著高于3组和对照组(P<0.05),VCL显著高于对照组(P<0.05);2组精子活力、VCL、VSL、直线运动精子活率显著高于1组、3组、对照组(P<0.05),VAP、ALH显著高于对照组(P<0.05);3组VCL显著高于对照组(P<0.05)。母羊妊娠率1,3组和对照组相比差异不显著(P>0.05);2组妊娠率最高,显著高于3组和对照组(P<0.05)。1,2,3组产羔率和羔羊成活率与对照组无显著差异(P>0.05)。说明冷冻稀释液中添加褪黑素1×10^(-7),1×10^(-5),1×10^(-3)mol/L均有利于提高冷冻精液解冻后的运动能力和输精的妊娠率,其中添加1×10^(-5)mol/L的效果最好。

In order to explore the effect of melatonin(MT)on the motility and pregnancy rate of frozen semen after thawing,Hu sheep semen was selected in the experiment,devided into 4 groups,which were melatonin 1×10^(-7)mol/L(group 1),1×10^(-5)mol/L(groups 2),1×10^(-3)mol/L(groups 3),control group(no melatonin).The semen of the 4 groups were frozen,and the sperm motility before and after thawing was measured in each group;The ewes were artificially inseminated with frozen sperm in each group,and the gestation and lambing performance were measured.The results showed that:the viability rate,mean curve velocity(VCL),mean linear velocity(VSL),mean path velocity(VAP),mean lateral swing(ALH)and linear velocity of sperm in Hu sheep semen before freezing were significantly higher than those of the groups after freezing(P<0.05).The sperm motility in group 1 was better than that in groups 3 and the control group,and the VCL was significantly better than the control group(P<0.05).The sperm motility,VCL,VSL,the motility rate of linear motile sperm in group 2 were significantly better than that of group 1,group 3 and control group(P<0.05),VAP and ALH were significantly better than those of control group(P<0.05).And VCL of group 3 was significantly better than that of control group(P<0.05).There were no significant difference in the pregnancy rate between groups 1 and 3 and the control group(P>0.05).The pregnancy rate of groups 2 was the highest,which was significantly higher than that of group 3 and control group(P<0.05).The lambing rate and lamb survival rate of groups 1,2 and 3 were not significantly different from those of the control group(P>0.05).It showed that adding melatonin 1×10^(-7),1×10^(-5)and 1×10^(-3)mol/L to the frozen diluent was beneficial to improve the motility of frozen semen and the pregnancy rate of insemination after thawing.1×10^(-5)mol/L had the best effect.