Scrotal surface thermography is a non-invasive method for assessing testicular thermoregulation in stallions; however, few studies have explored the application of this technique concerning the thermal physiology of equine reproductive systems. This study aimed to evaluate the consistency of testicular thermoregulation in stallions over a year using thermography to measure the scrotal surface temperature (SST). Moreover, we assessed the best region for measuring the surface body temperature compared with the SST. Ten light-breed stallions were used in the experiment. Thermographic images of the scrotal and body surfaces (neck and abdomen) were captured. Fresh, cooled and frozen–thawed semen samples were evaluated to verify the impact of thermoregulation on semen quality. Testicular thermoregulation was maintained throughout the year in stallions amidst changes in the external temperature, as evidenced by the weak correlation between the SST and ambient temperature. A lower correlation was observed between the environmental temperature and body surface temperature (BTS) obtained from the abdomen (BTS-A; R = .4772; p < .0001) than with that obtained from the neck (BTS-N; R = .7259; p < .0001). Moreover, both BTS-A and SST were simultaneously captured in a single image. The consistent quality of the fresh, cooled and frozen semen suggests efficient thermoregulation in stallions throughout the year.

中文翻译：

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使用热成像技术长期评估种马阴囊表面温度及其对精液质量的影响

阴囊表面热成像是一种用于评估种马睾丸温度调节的非侵入性方法；然而，很少有研究探讨该技术在马生殖系统热生理学方面的应用。本研究旨在使用热成像技术测量阴囊表面温度（SST）来评估公马一年内睾丸温度调节的一致性。此外，我们还评估了与海表温度相比测量表面体温的最佳区域。实验中使用了十匹轻种种马。拍摄阴囊和身体表面（颈部和腹部）的热成像图像。对新鲜、冷却和冻融的精液样本进行评估，以验证温度调节对精液质量的影响。在外部温度变化的情况下，种马的睾丸温度调节全年保持不变，海温与环境温度之间的弱相关性证明了这一点。从腹部获得的环境温度和体表温度 (BTS) (BTS-A; R  = .4772; p  < .0001) 之间的相关性低于从颈部获得的 (BTS-N; R  = .0001)。 7259；p  < .0001）。此外，BTS-A 和 SST 都是在一张图像中同时捕获的。新鲜、冷却和冷冻精液的质量始终如一，表明种马全年都能有效调节体温。