【摘要】 为探讨褪黑素（Melatonin,MT）对蛋鸡慢性热应激的影响，将60只海兰褐壳蛋鸡随机分为4组：对照组（Control）、热应激组（HS）、热应激褪黑素低剂量组(HS+MT 1 mg·kg^-1)和热应激褪黑素高剂量组(HS+MT5 mg·kg^-1)。结果表明，饲料中添加MT可提高热应激蛋鸡血清MT浓度、采食量和产蛋率。MT处理后，热应激蛋鸡血清中谷胱甘肽过氧化物酶（GSH-Px）和卵泡刺激素（FSH）水平显著升高，血清中皮质酮（CORT）、热休克蛋白70（HSP70）、丙二醛（MDA）、白细胞介素6（IL-6）和白细胞介素1β（IL-1β）水平显著降低。大黄卵泡（LYF）颗粒细胞层和卵泡膜层厚度增加。与HS组相比，HS+MT 1 mg·kg^-1组卵巢促性腺激素释放激素（GnRH）及其受体（GnRHR）、卵泡刺激素受体（FSHR）、糖蛋白激素受体（LHCGR）和雌激素受体2（ESR2）表达水平升高，HSP70表达水平降低。综上，外源性MT可有效增强热应激蛋鸡抗氧化和抗炎能力，调节免疫、蛋白质代谢和激素水平，提高生产性能。更多还原

【Abstract】 To investigate the effects of melatonin（MT） on chronic heat stress in laying hens, 60 Hyland’s brown-shelled laying hens were randomly divided into four groups: control group（Control）,heat stress group（HS）, heat stress melatonin low-dose group(HS+MT 1 mg·kg^-1), and heat stress melatonin high-dose group(HS+MT 5 mg·kg^-1). The results showed that the addition of MT to feed increased serum MT concentration, feed intake and egg production rate in heat-stressed laying hens.The serum levels of glutathione peroxidase（GSH-Px） and follicle-stimulating hormone（FSH） in heatstressed laying hens were significantly increased after MT treatment, and the serum levels of corticosterone（CORT）, heat-shock protein 70（HSP70）, malondialdehyde（MDA）, interleukin 6（IL-6）and interleukin 1β（IL-1β） levels were significantly decreased after MT treatment. The thickness of the granulosa cell layer and follicular membrane layer of the large yellow follicle（LYF） increased.Compared with the HS group, the expression levels of ovarian gonadotropin-releasing hormone（GnRH） and its receptor（GnRHR）, follicle-stimulating hormone receptor（FSHR）, glycoprotein hormone receptor（LHCGR）, and estrogen receptor 2（ESR2） were elevated in the HS+MT 1 mg·kg^-1 group, while the expression level of HSP70 was decreased. In conclusion, exogenous MT could effectively enhance the antioxidant and anti-inflammatory capacity, regulate immunity, protein metabolism and hormone levels, and improve production performance in heat-stressed laying hens.更多还原