Heat stress (HS) has a great influence on the etiology of male infertility. Coenzyme Q10 (CoQ10), known to have powerful antioxidant effects, has been reported to have such actions that are effective to treat infertility caused by HS. The aim of the present study was to investigate the antioxidative effect of CoQ10 on sperm quality, testicular antioxidant activities, and male fertility under HS. For this purpose, 18 mature male rabbits (aged 22 wk) of the Sinai Gabali breed were equally divided into 3 groups and placed at temperature-humidity index of 29 for 8 wk at a farm. The supplementation of CoQ10 at 0, 10, and 20 mg/kg of body weight was done in the first, second, and third groups, respectively. The results showed that the supplementation of CoQ10 had significant (P < 0.05) effect on semen quality factor (SQF) and testicular antioxidant activities by the supplementation of CoQ10. Moreover, a significant improvement in the concentration of testosterone, integrity of testicular DNA, and the expression of melatonin receptors was also observed, which were consistent with a significant improvement in buck fertility. The prolificacy was significantly increased (P < 0.05) in females when inseminated from bucks that were treated with CoQ10. Our results suggest that CoQ10 tends to decrease oxidative stress by enhancing testicular antioxidant activities, which are considered the most important factors for a buck's fertility. Hence, CoQ10 could be a suitable feed supplement to increase fertility, through enhancing the semen quality, in male rabbits and reducing the harmful effects of HS.

热应激（HS）对男性不育的病因有很大影响。辅酶 Q10 (CoQ10) 具有强大的抗氧化作用，据报道其具有治疗 HS 引起的不孕症的作用。本研究的目的是研究 CoQ10 对精子质量、睾丸抗氧化活性和 HS 下男性生育能力的抗氧化作用。为此，将 18 只西奈加巴利品种的成熟雄性兔（22 周龄）平均分为 3 组，并在一个农场以 29 的温湿度指数放置 8 周。第一、第二和第三组分别以 0、10 和 20 毫克/千克体重补充 CoQ10。结果表明，辅酶Q10的补充显着（P< 0.05) 补充 CoQ10 对精液质量因子 (SQF) 和睾丸抗氧化活性的影响。此外，还观察到睾酮浓度、睾丸 DNA 完整性和褪黑激素受体表达的显着改善，这与雄鹿生育力的显着改善一致。产率显着提高（P< 0.05) 在用辅酶 Q10 处理的雄鹿进行授精的雌性中。我们的研究结果表明，辅酶 Q10 倾向于通过增强睾丸抗氧化活性来降低氧化应激，这被认为是雄鹿生育能力的最重要因素。因此，辅酶Q10可以作为一种合适的饲料补充剂，通过提高雄性兔的精液质量和减少HS的有害影响来提高生育能力。