Jiménez-Rabadán P, Soler A J, Ramón M, García-Álvarez O, Maroto-Morales A, Iniesta-Cuerda M, Fernández-Santos M R, Montoro V, Pérez-Guzmán M D, Garde J J
Regional Center of Animal Selection and Reproduction (CERSYRA), JCCM, Avenida del Vino, s/n, 13300, Valdepeñas, Spain.
SaBio Group, National Wildlife Research Institute (IREC), CSIC-UCLM-JCCM, ETSIA, Campus Universitario s/n, 02071 Albacete, Spain.
Anim Reprod Sci. 2016 Apr;167:103-8. doi: 10.1016/j.anireprosci.2016.02.013. Epub 2016 Feb 16.
Semen collection for cryopreservation is a key step for small ruminant conservation programs. While in these species semen is mainly collected via artificial vagina (AV), electroejaculation (EE) provides a viable alternative for untrained males. Herein we investigated the effect of semen collection method on post-thaw sperm quality by comparing two small ruminant species, sheep and goats. Semen from Blanca-Celtibérica bucks and Manchega rams was collected by AV and EE on the same day and cryopreserved using a standard protocol. At thawing, sperm motion parameters were evaluated by CASA, whereas membrane stability (YO-PRO-1), sperm viability (propidium iodide, PI) and mitochondrial activity (Mitotracker Deep Red) were analyzed using flow cytometry. The semen collection method negatively affected post-thaw sperm quality in bucks but not in rams. Thus, in bucks, post-thaw sperm motility was higher for samples collected by AV as compared to those obtained via EE. Similarly, post-thaw sperm parameters evaluated by flow cytometry were worse for buck samples collected by EE than those collected by AV in the same species, or than ram samples regardless of collection method. These results suggest that ovine and caprine spermatozoa have a different response to the cryopreservation process depending upon the semen collection method used. We hypothesize that the EE procedure may lead to changes in the composition of the ejaculate in bucks that would make spermatozoa more susceptible to the cryopreservation process, whereas this procedure would have had no effect on ram spermatozoa. This assumption requires further investigation.
精液采集用于冷冻保存是小型反刍动物保护计划的关键步骤。在这些物种中，精液主要通过人工阴道（AV）采集，而电射精（EE）为未经训练的雄性动物提供了一种可行的替代方法。在此，我们通过比较绵羊和山羊这两种小型反刍动物，研究了精液采集方法对解冻后精子质量的影响。在同一天，通过AV和EE采集布兰卡-凯尔特伊比利亚公山羊和曼彻格公羊的精液，并使用标准方案进行冷冻保存。解冻时，通过计算机辅助精子分析（CASA）评估精子运动参数，而使用流式细胞术分析膜稳定性（YO-PRO-1）、精子活力（碘化丙啶，PI）和线粒体活性（线粒体深染剂）。精液采集方法对解冻后公山羊的精子质量有负面影响，但对公羊没有影响。因此，在公山羊中，与通过EE获得的样本相比，通过AV采集的样本解冻后精子活力更高。同样，在同一物种中，通过EE采集的公山羊样本经流式细胞术评估的解冻后精子参数比通过AV采集的样本更差，或者与无论采集方法如何的公羊样本相比也更差。这些结果表明，绵羊和山羊的精子对冷冻保存过程的反应因所使用的精液采集方法而异。我们假设，EE程序可能会导致公山羊射精成分发生变化，从而使精子更容易受到冷冻保存过程的影响，而该程序对公羊精子则没有影响。这一假设需要进一步研究。
