【摘要】 为了测定牛体外受精胚胎移植到受体母牛后的怀孕率和双胎率，本研究共进行了３个胚胎移植试验。试验１，测定新鲜胚胎移植后的怀孕效果。将１６０枚新鲜胚胎移植到８０头受体母牛（每头受体接受２枚胚胎），移植后６０～９０ｄ的怀孕率为６５％（５２／８０），其中双胎率为５０％（２／５２）。试验２，测定经室温保存４～１８ｈ的胚胎移植后的怀孕效果。供试验用的６８头受体母牛均于移植前７ｄ（即发情当天）进行人工授精。移植时每头受体牛接受１枚胚胎。移植后４０～６５ｄ的怀孕率为７６．５％（５２／６８），其中双胎率为６５．４％（３４／５２）。试验３，测定冷冻胚胎移植后的怀孕效果。将４５４枚冷冻胚胎移植到２２７头受体母牛，每头接受２枚冻胚。移植后５０～６０ｄ的怀孕率为６１．７％（１４０／２２７），其中双胎率为２５％（３５／１４０）。本研究结果表明，用完全体外化技术生产的牛胚胎移植到受体母牛后可获得满意的怀孕率和双胎率，这一技术将为加速向用牛生产的发展开辟一条崭新的途径。更多还原

【Abstract】 Three experiments were performed in the present study to determine the pregnancy and twinning rates after transfer of in vitro embryos to the recipients. Exp. 1,160 fresh embryos were non-surgically twin-transferred to 80 recipient cows and the pregnancy and twinning rates were 65% (52/80) and 50% (26/52), respectively 60￣90 days after transfer. Exp. 2,68 embryos stored at room temperature for 4￣18 h were transferred to 68 recipient cows that had already been artificially inseminated on the day of oestrus and the pregnancy and twinning rates were 76. 5% (52/68) and 65. 4% (34/52),respectively 40￣65 days following transfer. Exp. 3, 454 frozen-thawed embryos were twin-transferred to 227 recipients, 61.7 % (140/227) of pregnancy rate and results indicate that satisfactory pregnancy and twinning rates can be obtained after twin-transfer of in vitro embryos to recipients. It is anticipated that the technique of twin-transfer of in vitro embryos to recipients applied commercially in the field will have great impact on beef cattle production in the near future.更多还原