不同时间单次定时输精对绵羊受胎率的影响

Effects of single fixed-time artificial insemination at different time on ovine pregnant rate

采用孕酮阴道海绵栓与PMSG相结合的方法对湖羊和乌珠穆沁羊进行同期发情和定时输精,海绵栓埋置13 d后撤栓,同时肌肉注射PMSG 330 IU,在撤栓后36,48,58 h分别对试验羊进行单次阴道输精和腹腔镜子宫角输精,输精后40 d进行B超测孕并在分娩后统计产羔数。结果显示,在撤栓后58 h分别对湖羊和乌珠穆沁羊进行单次阴道输精可以得到较好的受胎率和产羔率(湖羊76.9%和266%,乌珠穆沁羊72.3%和124%)。所有试验羊在撤栓后48 h或58 h于腹腔镜子宫角输精的受胎率无显著性差异(湖羊94.8%和92.4%,乌珠穆沁羊89.2%和89.4%),但都显著高于撤栓后36 h的受胎率(湖羊55.6%,乌珠穆沁羊54.4%)。促黄体素释放激素A3(LRHA3)显著降低了湖羊阴道输精的妊娠率,但却提高了乌珠穆沁羊阴道输精的妊娠率,而对湖羊子宫角输精的妊娠率没有影响。结果表明,湖羊和乌珠穆沁羊在撤栓后58 h进行单次定时阴道输精,取得了较好的受胎率和产羔率,适宜在绵羊养殖场(户)大规模推广应用。

The effects of single fixed-time artificial insemination and luteinizing hormone releasing hormone A3(LRHA3)at different sponge withdrawal time on ovine pregnant rate and lambing rate were investigated in this study.Vaginal flugestone acetate sponge plug and pregnant mare serum gonadotropin(PMSG)were applied to estrus synchronization and fixed-time artificial insemination of Hu sheep and Wuzhumuqin sheep.The sponge plugs were removed 13 days after treatment and each sheep had an intramuscular injection of PMSG of 330 IU at sponge plug withdrawal.All of the sheep were fixed-time inseminated at 36,48 and 58 h after sponge withdrawal.Pregnant rate was recorded 40 day after insemination using B-mode ultrasound tomography.Lambing rate was recorded at delivery.The result showed that Hu sheep and Wuzhumuqin sheep had better pregnant rate and lambing rate(76.9%and 266%for Hu sheep,72.3%and 124%for Wuzhumuqin sheep,respectively)using a single vaginal insemination after 56 h sponge withdrawal.The pregnant rates of Hu sheep(94.8%and 92.4%)and Wuzhumuqin sheep(89.2%and 89.4%)using laparoscopic intrauterine insemination after 48 h and 56 h sponge withdrawal were not significantly different but higher than those of 36 hafter sponge withdrawal(55.6%for Hu sheep,54.4%for Wuzhumuqin sheep).The injection of LRHA3 had no effects on the pregnant rate of Hu sheep using intrauterine insemination,however it decreased the pregnant rate of Hu sheep and increased the pregnant rate of Wuzhumuqin sheep using vaginal insemination.In conclusion,a single fixed-time vaginal insemination 58 hafter sponge withdrawal can produce better pregnant rate and lambing rate in Hu sheep and Wuzhumuqin sheep.This protocol can be popularized in sheep farm.