This study examines the influence of administering testosterone at the end of the mating season, on the responses (morphometric and functional) of ram and buck sperm to freezing-thawing. Five rams were administered 25 mg testosterone propionate (TP) subcutaneously in 2 mL of olive oil twice per week (Monday and Thursday) from October 1 to 31; 5 bucks received exactly the same treatment but from November 1 to 30. Control groups were administered 2 mL of olive oil without TP twice per week over the same period. In the rams, no significant differences were seen in plasma testosterone between the treated and control groups during treatment (0.8 ± 0.2 ng/mL vs 1.5 ± 0.5 ng/mL; P > 0.05). Significant differences were seen in this respect, however, in the bucks (4.3 ± 0.8 ng/mL and 6.9 ± 0.9 ng/mL; P < 0.05). In the rams, TP treatment increased (P < 0.05) the straight-line velocity (VSL), linearity (LIN), straightness (STR) and wobble (WOB) values in fresh sperm samples. Similarly, in the frozen-thawed samples, TP treatment increased the VSL, average path velocity (VAP), LIN and WOB values (P < 0.05) compared with controls. In the bucks, treatment with TP had no effect on any measured variable in fresh sperm; frozen-thawed sperm, however, returned greater VSL, LIN, STR, and WOB values (P < 0.05) than did controls. In the rams, treatment with TP led to a reduction in all fresh sperm head morphometric variables (P < 0.05). Freezing-thawing further reduced (P < 0.05) all morphometric variables in both the control and treated groups. In the bucks, treatment with TP increased (P < 0.05) the length, area, and perimeter of fresh sperm cells, unlike that seen in ram sperm. Compared with fresh sperm, freezing-thawing led to reduced (P < 0.05) morphometric variables in both the control and treated bucks, except for the sperm head width, which in the controls remained unchanged. In conclusion, TP treatment at the end of the mating season affected fresh sperm quality, in both Spanish Merino rams and Murciano-Granadina bucks, in a species-specific manner, but improved the sperm kinetic variables after freezing-thawing in both species, apparently improving sperm cryoresistance. Treatment with TP affects the dimensions of the sperm head in a species-specific manner.

这项研究探讨了交配季节结束时施用睾丸激素对公羊和巴克精子对冻融的反应（形态和功能）的影响。从10月1日至31日，每周两次（星期一和星期四）对5只公羊皮下注射2mL橄榄油中的25 mg丙酸睾丸酮（TP）；5美元接受了完全相同的治疗，但从11月1日至30日。对照组在同一时期内每周两次给予2 mL不含TP的橄榄油。在公羊中，治疗期间和对照组之间的血浆睾丸激素没有显着差异（0.8±0.2 ng / mL与1.5±0.5 ng / mL；P > 0.05）。在这方面看到了显着差异，但在雄鹿（4.3±0.8 ng / mL和6.9±0.9 ng / mL；P<0.05）。在公羊中，TP处理增加了新鲜精子样品的直线速度（VSL），线性（LIN），直线度（STR）和摆动（WOB）值（P <0.05）。同样，在冷冻融化的样品中，与对照组相比，TP处理增加了VSL，平均路径速度（VAP），LIN和WOB值（P <0.05）。在雄鹿中，TP处理对新鲜精子的任何测量变量均无影响。然而，冻融的精子比对照返回更大的VSL，LIN，STR和WOB值（P <0.05）。在公羊中，TP处理导致所有新鲜精子头部形态计量变量的减少（P <0.05）。冻融进一步减少（P<0.05）对照组和治疗组的所有形态计量学变量。在雄鹿中，用TP处理可以增加（P <0.05）新鲜精子细胞的长度，面积和周长，这与公羊精子不同。与新鲜精子相比，冻融导致精子减少（P<0.05）对照和处理后的雄鹿的形态计量变量，但精子头部宽度除外，对照中的精子头宽度保持不变。总之，在交配季节结束时，TP处理以特定于物种的方式影响了西班牙美利奴羊公羊和Murciano-Granadina雄鹿的新鲜精子质量，但明显改善了两个物种冻融后的精子动力学变量。改善精子抗寒性。TP处理以特定物种的方式影响精子头部的尺寸。