Abella D Fernández, Da Costa M, Guérin Y, Dacheux J L
1Secretariado Uruguayo de la Lana,Rbla Baltasar Brum 3764,11800 Montevideo,Uruguay.
2PDU Ruminates,Universidad de la Republica del Uruguay,50000 Salto,Uruguay.
Animal. 2015 Feb;9(2):313-9. doi: 10.1017/S1751731114002109. Epub 2014 Sep 25.
In vitro preservation of the male gamete is a challenge in the development of artificial insemination techniques for domestic animals. Specific strategies and diluents have been developed for the preservation of the fertilizing ability of the semen for each species. However, the epididymal medium has been demonstrated to be the best sperm environment to maintain sperm viability over several days and weeks for mammals. The aims of this study were to evaluate the motility and in vivo fertility of ram epididymal spermatozoa when the semen was stored for up to 4 days at 4°C undiluted in epididymal plasma. The study was undertaken with two ovine breeds (Ile de France and Corriedale). The motility of epididymal spermatozoa was better preserved in the undiluted epididymal fluid than when epididymal spermatozoa were diluted in classic ovine extender such as skim milk. During storage, the decrease in the percentage of motile sperm was lower if the epididymal spermatozoa were collected immediately after epididymal sampling than 24 h after castration or animal death. The fertility obtained after cryopreservation of the stored sperm and subsequent intrauterine insemination ranged from 55% to 24% following 24 to 96-h sperm storage. There was a linear regression relationship between fertility and the number of motile sperm inseminated for both breeds. These results show that it is possible to keep epididymal sperm motile and fertile for several days without dilution. Such a method of sperm preservation could be a final possibility for animals of high genetic value or for endangered species when the collection of semen before death of the animal is not possible.
家畜人工授精技术发展中，雄性配子的体外保存是一项挑战。针对每个物种，已开发出特定的保存精液受精能力的策略和稀释剂。然而，对于哺乳动物而言，附睾介质已被证明是在数天和数周内维持精子活力的最佳精子环境。本研究的目的是评估在4℃下，将附睾精子在附睾血浆中未稀释保存长达4天时的活力和体内受精能力。该研究选用了两个绵羊品种（法国岛羊和考力代羊）。与将附睾精子稀释于脱脂乳等经典绵羊稀释液中相比，未稀释的附睾液能更好地保存附睾精子的活力。在保存过程中，如果附睾采样后立即收集附睾精子，与去势或动物死亡24小时后收集相比，活动精子百分比的下降更低。储存精子冷冻保存并随后进行子宫内授精后，在精子储存24至96小时后，受精率在55%至24%之间。两个品种的受精率与授精时活动精子数量之间均存在线性回归关系。这些结果表明，不进行稀释可使附睾精子在数天内保持活力和受精能力。对于高遗传价值的动物或濒危物种，当无法在动物死亡前采集精液时，这种精子保存方法可能是最后的选择。
