Environmental influence on the avian reproductive system is well recognised. This study investigates the effects of ambient temperature on egg quality in the native Thai Chicken (Gallus domesticus). Effects on prolactin (PRL) and ovarian steroids in chickens housed under different temperatures were also elucidated. Sixty female chickens were divided into four groups. Groups 1, 2, and 3 were reared under controlled temperatures of 35±2 °C, 31±2 °C, and 27±2 °C, respectively. Group 4 was reared under an uncontrolled natural temperature (approximately 27 °C). Blood samples were collected from each chicken once a week for 11 weeks, and plasma PRL, oestradiol (E), progesterone (P), and testosterone (T) levels were determined utilising enzyme-linked immunosorbent assays. The results revealed that E levels were significantly higher in chickens reared under low ambient temperature (27 °C) when compared with those exposed to 31 °C and 35 °C. No significant differences in PRL, P, and T levels were observed. Egg quality was affected by high ambient temperature. Eggshell thickness of chickens housed at 35 °C was thinner than those of other groups. These results indicate that changes in ambient temperature affect circulating levels of E but not PRL, P, and T. Thermally-stressed environments with high temperatures therefore impact egg quality in the native Thai chicken by reducing eggshell thickness.

中文翻译：

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温度对泰国本土鸡生殖激素和蛋品质的影响

环境对鸟类生殖系统的影响是众所周知的。本研究调查了环境温度对泰国本土鸡 (Gallusdomesticus) 鸡蛋质量的影响。还阐明了在不同温度下饲养的鸡对催乳素 (PRL) 和卵巢类固醇的影响。六十只母鸡被分成四组。第 1、2 和 3 组分别在 35±2°C、31±2°C 和 27±2°C 的受控温度下饲养。第 4 组是在不受控制的自然温度（约 27 °C）下饲养的。每周从每只鸡采集一次血样，持续 11 周，并使用酶联免疫吸附测定法测定血浆 PRL、雌二醇 (E)、孕酮 (P) 和睾酮 (T) 水平。结果表明，与暴露于 31°C 和 35°C 的鸡相比，在低环境温度 (27°C) 下饲养的鸡的 E 水平显着更高。未观察到 PRL、P 和 T 水平的显着差异。鸡蛋质量受高环境温度影响。35℃饲养的鸡的蛋壳厚度比其他组的鸡更薄。这些结果表明，环境温度的变化会影响 E 的循环水平，但不会影响 PRL、P 和 T 的循环水平。因此，高温的热应激环境会通过降低蛋壳厚度来影响泰国本土鸡的鸡蛋质量。35℃饲养的鸡的蛋壳厚度比其他组的鸡更薄。这些结果表明，环境温度的变化会影响 E 的循环水平，但不会影响 PRL、P 和 T 的循环水平。因此，高温的热应激环境会通过降低蛋壳厚度来影响泰国本土鸡的鸡蛋质量。35℃饲养的鸡的蛋壳厚度比其他组的鸡更薄。这些结果表明，环境温度的变化会影响 E 的循环水平，但不会影响 PRL、P 和 T 的循环水平。因此，高温的热应激环境会通过降低蛋壳厚度来影响泰国本土鸡的鸡蛋质量。