Department of Animal Medicine and Surgery, University of Murcia, Murcia, Spain.
Department of Research and Development Selección Batallé S.A., Girona, Spain.
Theriogenology. 2014 Apr 1;81(6):832-9. doi: 10.1016/j.theriogenology.2013.12.017. Epub 2013 Dec 28.
This study aimed to evaluate the effectiveness of superovulation protocols in improving the efficiency of embryo donors for porcine nonsurgical deep-uterine (NsDU) embryo transfer (ET) programs. After weaning (24 hours), purebred Duroc sows (2-6 parity) were treated with 1000 IU (n = 27) or 1500 IU (n = 27) of eCG. Only sows with clear signs of estrus 4 to 72 hours after eCG administration were treated with 750 IU hCG at the onset of estrus. Nonhormonally treated postweaning estrus sows (n = 36) were used as a control. Sows were inseminated and subjected to laparotomy on Days 5 to 6 (Day 0 = onset of estrus). Three sows (11.1%) treated with the highest dosage of eCG presented with polycystic ovaries without signs of ovulation. The remaining sows from nonsuperovulated and superovulated groups were all pregnant, with no differences in fertilization rates among groups. The number of CLs and viable embryos was higher (P < 0.05) in the superovulated groups compared with the controls and increased (P < 0.05) with increasing doses of eCG. There were no differences among groups in the number of oocytes and/or degenerated embryos. The number of transferable embryos (morulae and unhatched blastocysts) obtained in pregnant sows was higher (P < 0.05) in the superovulated groups than in the control group. In all groups, there was a significant correlation between the number of CLs and the number of viable and transferable embryos, but the number of CLs and the number of oocytes and/or degenerated embryos were not correlated. A total of 46 NsDU ETs were performed in nonhormonally treated recipient sows, with embryos (30 embryos per transfer) recovered from the 1000-IU eCG, 1500-IU eCG, and control groups. In total, pregnancy and farrowing rates were 75.1% and 73.2%, respectively, with a litter size of 9.4 ± 0.6 piglets born, of which 8.8 ± 0.5 were born alive. There were no differences for any of the reproductive parameters evaluated among groups. In conclusion, our results demonstrated the efficiency of eCG superovulation treatments in decreasing the donor-to-recipient ratio. Compared with nonsuperovulated sows, the number of transferable embryos was increased in superovulated sows without affecting their quality and in vivo capacity to develop to term after transfer. The results from this study also demonstrate the effectiveness of the NsDU ET procedure used, making possible the commercial use of ET technology by the pig industry.
本研究旨在评估超排卵方案对提高猪非手术深部子宫（NsDU）胚胎移植（ET）计划胚胎供体效率的影响。断奶后 24 小时（24 小时），对纯种杜洛克母猪（2-6 胎）进行 1000IU（n=27）或 1500IU（n=27）eCG 处理。只有在 eCG 给药后 4 至 72 小时出现明显发情迹象的母猪，在发情开始时用 750IU hCG 处理。未用激素处理的断奶后发情母猪（n=36）作为对照。母猪在第 5 至 6 天（发情开始日为第 0 天）进行授精和剖腹手术。用最高剂量 eCG 处理的 3 头母猪出现多囊卵巢，无排卵迹象。未超排卵和超排卵组的其余母猪均怀孕，各组的受精率无差异。与对照组相比，超排卵组的 CL 数和活胚胎数较高（P<0.05），且随着 eCG 剂量的增加而增加（P<0.05）。各组卵母细胞和/或退化胚胎数量无差异。在怀孕母猪中获得的可移植胚胎（桑葚胚和孵育囊胚）数量在超排卵组中高于对照组（P<0.05）。在所有组中，CL 数与活胚胎和可移植胚胎数之间均存在显著相关性，但 CL 数与卵母细胞和/或退化胚胎数之间无相关性。对未用激素处理的受体母猪进行了 46 次非手术深部子宫 ET，从 1000IU eCG、1500IU eCG 和对照组中回收 30 个胚胎进行移植。总共，妊娠和分娩率分别为 75.1%和 73.2%，产仔数为 9.4±0.6 头，其中 8.8±0.5 头活产。各组的任何繁殖参数均无差异。总之，我们的结果表明 eCG 超排卵处理在降低供体与受体的比例方面是有效的。与未超排卵的母猪相比，超排卵母猪的可移植胚胎数量增加，而胚胎质量和体内发育到足月的能力不受影响。本研究的结果还证明了所使用的非手术深部子宫 ET 程序的有效性，使猪业能够商业化使用 ET 技术。
