The mechanism by which the content of the major groups of seminal plasma proteins in stallion semen changes between the breeding and non-breeding seasons remains unknown. Here, we investigated the proportions of non-heparin-binding, phosphorylcholine-binding, and heparin-binding proteins in seminal plasma with the aim of relating them to sperm quality and testosterone levels in good and bad freezer stallions. Only minor variations in the major protein groups were found between the breeding and non-breeding seasons. In the non-breeding season, a higher content of a subset of non-heparin binding proteins as well as of heparin-binding proteins was found. Analysis of semen characteristics revealed a somewhat contrasting picture. While only minor variations in sperm kinematics and sperm morphology were found between seasons, the flow-cytometric measurements of mitochondrial membrane potential and also, to some extent, reactive oxygen species production indicated lower sperm quality in the breeding season. Chromatin integrity and testosterone levels were unchanged between seasons. The results suggest that stallion ejaculates could be used year-round for freezing, since only minor differences in protein composition exist between the breeding and non-breeding seasons, as well as between good and bad freezers. In addition, sperm quality is not impaired during the non-breeding season.

中文翻译：

---

季节对种马精浆蛋白的比例没有有害影响

种马精液中主要组精浆蛋白含量在繁殖和非繁殖季节之间变化的机制尚不清楚。在这里，我们研究了精浆中非肝素结合蛋白、磷酸胆碱结合蛋白和肝素结合蛋白的比例，目的是将它们与好的和坏的冷冻种马的精子质量和睾酮水平联系起来。在繁殖和非繁殖季节之间只发现主要蛋白质组的微小变化。在非繁殖季节，发现非肝素结合蛋白和肝素结合蛋白的子集含量较高。精液特征的分析揭示了一个有点对比的图片。虽然在不同季节之间只发现精子运动学和精子形态的微小变化，线粒体膜电位的流式细胞仪测量以及在某种程度上，活性氧的产生表明繁殖季节精子质量较低。染色质完整性和睾酮水平在季节之间没有变化。结果表明，种马的精液可以全年用于冷冻，因为繁殖季节和非繁殖季节之间以及冷冻机的好坏之间仅存在蛋白质成分的微小差异。此外，在非繁殖季节，精子质量不会受到影响。结果表明，种马的精液可以全年用于冷冻，因为繁殖季节和非繁殖季节之间以及冷冻机的好坏之间仅存在蛋白质成分的微小差异。此外，在非繁殖季节，精子质量不会受到影响。结果表明，种马的精液可以全年用于冷冻，因为繁殖季节和非繁殖季节之间以及冷冻机的好坏之间仅存在蛋白质成分的微小差异。此外，在非繁殖季节，精子质量不会受到影响。