Departamento de Reproducción Animal, INIA, Madrid, Spain.
Theriogenology. 2011 Dec;76(9):1695-705. doi: 10.1016/j.theriogenology.2011.07.001.
The present work examines the relationship between seasonal changes in testicular function, accessory gland size, and horn growth in Iberian ibexes, as well as the relationship between these changes and the resistance of ibex spermatozoa to freezing-thawing. The size of the bulbourethral glands and seminal vesicles showed pronounced monthly variation (P < 0.001), which was correlated positively with the plasma testosterone concentration (P < 0.001) and scrotal circumference (P < 0.001). The size of the accessory sex glands peaked during the autumn. Overall, semen quality was markedly improved during autumn and winter. When horn growth was at a minimum during autumn and winter, semen quality and accessory gland size were all increased compared to in spring and summer. However, increased plasma testosterone levels in the autumn were strongly associated with reduced sperm freezability; thus, the cryosurvival of spermatozoa collected during the autumn was poorer than at other times of the year. In winter, however, when the plasma testosterone concentration fell to baseline, the negative effects of cryopreservation on the percentage of motile spermatozoa and on the integrity of the plasma membrane of frozen-thawed sperm cells were significantly less intense (P < 0.05). These findings show a clear relationship between the functional and morphological status of the different parts of the reproductive tract that optimises reproductive function during the breeding season in the ibex male. They also show that winter is the most suitable season for the collection and cryopreservation of ibex spermatozoa.
本研究探讨了伊比利亚野山羊季节性睾丸功能、附属性腺大小和角生长变化之间的关系，以及这些变化与野山羊精子抗冻融能力之间的关系。精囊和前列腺的大小呈现出明显的月度变化（P < 0.001），与血浆睾酮浓度（P < 0.001）和阴囊周长（P < 0.001）呈正相关。附属性腺的大小在秋季达到峰值。总的来说，秋季和冬季的精液质量明显改善。当秋季和冬季角生长处于最低水平时，与春季和夏季相比，精液质量和附属性腺大小都有所增加。然而，秋季血浆睾酮水平升高与精子冻融能力降低密切相关；因此，秋季采集的精子的冷冻存活率比一年中的其他时间差。然而，在冬季，当血浆睾酮浓度降至基线时，冷冻对精子活力和冻融精子细胞膜完整性的负面影响显著减弱（P < 0.05）。这些发现表明，伊比利亚野山羊雄性在繁殖季节中，生殖道不同部位的功能和形态状态之间存在明显的关系，这优化了繁殖功能。它们还表明，冬季是采集和冷冻保存野山羊精子的最佳季节。
