冷冻精液输精深度和时间对蒙古羊受胎率的影响

Effects of Insemination Depth and Time on Conception Rate of Mongolian Sheep Inseminated with Frozen Semen

[目的]研究冷冻精液输精深度和时间对蒙古羊受胎率的影响。[方法]选取体况健康、繁殖机能正常的蒙古羊母羊作为试验动物,采用孕酮海绵栓对受体母羊进行同期发情处理。应用常规人工输精法(n=135)、过子宫颈输精法[过子宫颈第一皱褶(1~2 cm)输精(n=120),过子宫颈第二到第三皱褶(3~4 cm)输精(n=120)]、腹腔镜辅助子宫内输精法(n=128)对发情后的母羊进行冷冻精液人工授精。接受常规人工输精法和过子宫颈输精法处理的受体母羊在发情后约14 h和22 h各输精1次,接受腹腔镜辅助子宫内输精法处理的受体母羊在发情后30~36 h输精1次。输精后40 d用B超仪检测母羊妊娠情况,计算并比较接受不同输精方法处理母羊的受胎率。[结果]腹腔镜辅助子宫内输精法的受体母羊受胎率平均值最高,为60.2%;其次为过子宫颈第二到第三皱褶(3~4 cm)输精,受胎率平均值为58.3%;过子宫颈第一皱褶(1~2 cm)输精和常规输精法的受体母羊受胎率平均值分别为37.5%和36.3%。统计学分析表明,腹腔镜辅助子宫内输精法和过子宫颈第二到第三皱褶(3~4 cm)输精的受体母羊受胎率平均值显著(P<0.05)高于常规输精法和过子宫颈第一皱褶(1~2 cm)输精。[结论]蒙古羊母羊发情后30~36 h采用腹腔镜辅助子宫内输精法完全穿刺子宫颈输精1次,可获得比常规输精法更高的受胎率;采用过子宫颈输精法在母羊发情后约14 h和22 h各输精1次,当授精深度接近4 cm时可达到与腹腔镜辅助子宫内输精法接近的受胎率。

[Objective]To assess the effects of insemination depth and time on conception rate of Mongolian sheep inseminated with frozen semen.[Method]Health Mongolian ewes with normal reproductive capacity were chosen as experimental animals and were subjected to estrus synchronization using progesterone sponges.The ewes were artificially inseminated with frozen semen after estrus using conventional artificial insemination method(n=135),transcervical insemination method[transcervical first fold(1-2 cm)insemination(n=120),and transcervical second to third fold(3-4 cm)insemination(n=120)],and laparoscopically assisted intrauterine insemination method(n=128),respectively.The recipient ewes receiving conventional artificial insemination and transcervical insemination were separately inseminated once around 14 h and 22 h after estrus,and those receiving laparoscopically assisted intrauterine insemination were inseminated once during 30 h to 36 h after estrus.B-ultrosonic examination was carried out at 40 d after insemination,and the conception rates of the ewes inseminated by different methods were calculated and statistically compared.[Result]The highest average conception rate was observed in the ewes receiving laparoscopically assisted intrauterine insemination(60.2%),followed by those receiving transcervical second to third fold(3-4 cm)insemination(58.3%);the average conception rates of the ewes receiving transcervical first fold(1-2 cm)insemination and conventional artificial insemination were 37.5%and 36.3%,respectively.The statistical analysis demonstrated that the average conception rates of the ewes receiving laparoscopically assisted intrauterine insemination and transcervical second to third fold(3-4 cm)insemination were significantly(P<0.05)higher than those of the ewes receiving conventional artificial insemination and transcervical first fold(1-2 cm)insemination.[Conclusion]For Mongolian ewes,laparoscopically assisted intrauterine insemination method(inseminated once during 30 h to 36 h after estrus)that completely penetrates cervix obtains higher conception rate in comparison with conventional artificial insemination method;transcervical insemination method(separately inseminated once around 14 h and 22 h after estrus)with depth of nearing 4 cm achieves similar conception rate to laparoscopically assisted intrauterine insemination method.