Abstract Acute heat stress (AHS) is known to affect rabbit production and well-being negatively. Yet, early acute heat stress effect on later physiological response is poorly studied. Our study aimed to provide more knowledge of rabbit physiological response to early acute heat stress in two distinguished rabbit breeds. A total of 120 males of New Zealand White (NZW) and Baladi Black (BB) rabbits five weeks old were recruited and randomly divided into two sub-groups, control groups (Control) reared in a controlled environmental chamber 28 °C, and 40% RH and early acute heat stress groups (HS) exposed to 36 °C and 62% RH for 6 hours. At 13 weeks, rabbits of all groups were subjected to the same AHS conditions. Our results, irrespective of breeding differences, demonstrate a significant (p < .05) increase in inflammation markers (TNFα, IL-6 and lipid peroxidation), acute-phase proteins (ceruloplasmin, α-1-acid glycoprotein), and DNA fragmentation with a significant reduction in liver antioxidant enzymes concentrations (glutathione reduced, superoxide dismutase, and catalase) in HS groups compared to breed relative control groups. Furthermore, when all experimental groups at 13 weeks of age were subjected to the same stress conditions, the early HS group showed the same significant adverse physiological effects. It can be suggested that rabbits from different genetic groups are vulnerable to acute heat stress exposure at the early stage of life compared to later stages. Highlights Heat stress is one of the most critical issues facing rabbit production. Exposure young rabbits to acute heat stress had adverse effects on physiological parameters in later life. Rabbits exposed to acute heat stress at an early age did not produce thermo-tolerance ability to later time heat exposure.

中文翻译：

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两个遭受急性热应激的兔品种的肝脏急性期反应、抗氧化生物标志物和 DNA 片段化

摘要 众所周知，急性热应激 (AHS) 会对兔的生产和健康产生负面影响。然而，早期急性热应激对后期生理反应的影响研究甚少。我们的研究旨在提供更多关于两种不同品种兔品种兔对早期急性热应激的生理反应的知识。招募 120 只 5 周龄的新西兰白兔 (NZW) 和巴拉迪黑兔 (BB) 的雄性，随机分为两个亚组，对照组（Control）饲养在 28°C 的受控环境室中，40 % RH 和早期急性热应激组 (HS) 暴露于 36 °C 和 62% RH 6 小时。在第 13 周时，所有组的兔子都接受相同的 AHS 条件。我们的结果，无论育种差异如何，都表明炎症标志物（TNFα、IL-6 和脂质过氧化）、急性期蛋白（铜蓝蛋白、α-1-酸性糖蛋白）和 DNA 片段化，与 HS 组相比，肝脏抗氧化酶浓度（谷胱甘肽还原、超氧化物歧化酶和过氧化氢酶）显着降低培育相对对照组。此外，当所有 13 周龄的实验组都处于相同的应激条件下时，早期 HS 组表现出同样显着的不利生理效应。可以表明，与后期阶段相比，来自不同遗传群体的兔子在生命早期阶段更容易受到急性热应激暴露的影响。亮点 热应激是兔生产面临的最关键问题之一。幼兔暴露于急性热应激对晚年的生理参数有不利影响。