Lopes E de P, Siqueira J B, Pinho R O, Guimarães J D, Rocha A N, de Carvalho G R, Torres C A A
Ms Autonomous Veterinary, Zootecnia/UNESP - Botucatu, SP, Brasil.
Reprod Domest Anim. 2011 Apr;46(2):261-7. doi: 10.1111/j.1439-0531.2010.01656.x.
The objective of this study is to evaluate the reproductive efficiency in donors and recipient Mangalarga Marchador mares in commercial programmes of embryo transfer (ET) and the effects of some reproductive characteristics and ET methodology on conception rates in the recipient mares. A total of 1140 flushing procedures were performed and 830 embryos (72.8%) were recovered. There were no differences between the rates of embryonic recovery in the different breeding seasons (p > 0.05) and 92.8% of the recovered embryos were 8-9 days old. There was no difference in the embryonic recovery regarding the collection order from the first to the ninth embryo collection along the breeding season, as well as among mares inseminated during the foal heat or subsequent cycles (p > 0.05). Pregnancy rates observed in the total period of all reproductive seasons at 15, 30, 45 and 60 days of pregnancy were 73.4, 69.9, 66.7 and 64.5%, respectively. Differences in pregnancy rate and early embryonic loss rates were not observed between embryos transferred immediately after collection (66.8% and 13.5%) and embryos transported at room temperature for periods of < 1 h (62.9% and 14.4%; p > 0.05). Pregnancy rates were higher when the interval between ovulations of donor and recipient mares remained between -3 and -2 days (p < 0.05), and the lowest rates were observed for intervals of -6 days (p < 0.05) with intermediary values for intervals of -1, 0 and +1 (p > 0.05). Embryonic loss rates, however, did not differ between intervals of ovulation's synchronism between donor and recipient mares (p > 0.05). This flexibilization in the ovulatory synchronism between donor and recipient mares optimizes the use of recipient mares, thus reducing costs and facilitating management of horse breeding farms.
本研究的目的是评估在商业化胚胎移植（ET）项目中供体和受体曼加腊加马驹母马的繁殖效率，以及一些繁殖特征和ET方法对受体母马受孕率的影响。总共进行了1140次冲洗程序，回收了830枚胚胎（72.8%）。不同繁殖季节的胚胎回收率之间没有差异（p>0.05），回收的胚胎中有92.8%为8-9日龄。在繁殖季节从第一个到第九个胚胎采集的采集顺序方面，以及在产后发情期或随后周期授精的母马之间，胚胎回收率没有差异（p>0.05）。在所有繁殖季节的整个时期，怀孕15、30、45和60天时观察到的怀孕率分别为73.4%、69.9%、66.7%和64.5%。采集后立即移植的胚胎（66.8%和13.5%）与在室温下运输<1小时的胚胎（62.9%和14.4%；p>0.05）之间，未观察到怀孕率和早期胚胎损失率的差异。当供体和受体母马排卵间隔保持在-3至-2天之间时，怀孕率较高（p<0.05），而间隔为-6天时观察到的怀孕率最低（p<0.05），间隔为-1、0和+1天时为中间值（p>0.05）。然而，供体和受体母马排卵同步间隔之间的胚胎损失率没有差异（p>0.05）。供体和受体母马排卵同步的这种灵活性优化了受体母马的使用，从而降低了成本并便于马场管理。
