Madkour Mahmoud, Aboelazab Osama, Abd El-Azeem Nafisa, Younis Eman, Shourrap Mohamed
Animal Production Department, National Research Centre, Giza, Egypt.
Department of Therapeutic Chemistry, National Research Centre, Giza, Egypt.
J Anim Physiol Anim Nutr (Berl). 2023 Jan;107(1):182-191. doi: 10.1111/jpn.13679. Epub 2022 Jan 6.
There are little data about antioxidants' status responses to early thermal conditioning (TC) on broiler chickens. Therefore, the present study was conducted to investigate the different time ages of thermal conditioning on antioxidants responses and the growth rate of broiler chicks. A total of two hundred forty-one-day-old male broiler chicks (Cobb 500) weighed on average 51.5 ± 0.5g were randomly distributed into four equal groups (60 chicks each), and chicks of each group were ranked in five replicates. The first group reared under the ambient temperature, while the second, third and fourth groups (TC3, TC5 and TC7) were subjected to early-age thermal conditioning at 39°C for 6 h on the third, fifth and seventh day of age respectively. Broilers were fed ad-libitum, and drinking water was a free choice during the experimental period. At the end of the experimental period that lasted 5 weeks, all experimental groups were exposed to heat challenge at 36°C for 6 h. Early-age thermal conditioning did not affect growth performance. Plasma corticosterone elevation in TC5 (as a post-challenge response) was the lowest among the experimental groups. Hepatic malondialdehyde significantly increased in TC5 and TC7 groups both at the post-conditioning stage and at the end of the experimental period. Hepatic glutathione, glutathione S-transferases, catalase and superoxide dismutase significantly decreased by early-age thermal conditioning compared with non-conditioned broilers. Microscopic examination of the liver sections from broilers chickens in TC5 and TC7 groups showed all the basic features of normal liver tissue, while the control and TC3 groups showed few necrotic areas. It could be concluded that early-age thermal conditioning at 39°C for 6 h on the fifth day of age could improve the antioxidant defence system of broilers without any adverse effects on growth performance.
关于抗氧化剂状态对肉鸡早期热应激适应（TC）的反应，相关数据较少。因此，本研究旨在探讨不同时间阶段的热应激适应对肉鸡抗氧化剂反应及生长速率的影响。总共240只1日龄雄性肉鸡（科宝500），平均体重51.5±0.5克，随机分为四组（每组60只），每组雏鸡再分为五个重复。第一组在环境温度下饲养，而第二、第三和第四组（TC3、TC5和TC7）分别在第3、5和7日龄时于39°C进行6小时的早期热应激适应。在实验期间，肉鸡自由采食，饮用水可自由选择。在持续5周的实验期结束时，所有实验组在36°C下接受6小时的热应激挑战。早期热应激适应不影响生长性能。在实验组中，TC5组（作为应激后反应）的血浆皮质酮升高幅度最小。在热应激适应后阶段和实验期结束时，TC5组和TC7组的肝脏丙二醛显著增加。与未进行热应激适应的肉鸡相比，早期热应激适应使肝脏谷胱甘肽、谷胱甘肽S -转移酶、过氧化氢酶和超氧化物歧化酶显著降低。对TC5组和TC7组肉鸡肝脏切片的显微镜检查显示具有正常肝组织的所有基本特征，而对照组和TC3组显示出少量坏死区域。可以得出结论，在第5日龄时于39°C进行6小时的早期热应激适应可改善肉鸡的抗氧化防御系统，且对生长性能无任何不利影响。
