Animal Physiology Department, Federal University of Agriculture, Abeokuta, Nigeria.
Animal Nutrition Department, Federal University of Agriculture, Abeokuta, Nigeria.
Stress. 2024 Jan;27(1):2319803. doi: 10.1080/10253890.2024.2319803. Epub 2024 Apr 17.
Heat stress has been ranked as a critical environmental issue confronting chicken farmers worldwide because of its detrimental effect on the growth, performance and health of the birds. This study evaluated the effects of early-age thermal manipulation (EATC) and supplemental antioxidants on the physiological responses of broilers in a hot tropical environment. A total of 300 day-old Ross broiler chicks were allocated to five thermal and dietary treatments, having 5 replicates of twelve birds each. The treatments were: chicks reared using the conventional method (CC), chicks exposed to early thermal manipulation with a temperature of 38 °C at day 5 with no antioxidant supplementation (TC), TC plus vitamin E at 250 mg/kg of feed (TV), TC plus selenium at 0.5 mg/kg of feed (TS) and the combination of TS and TV(TVS). The experiment was laid out in a Completely Randomized Design and data collected were analyzed using SAS (2008). The results showed that TVS broilers had significantly higher ( < 0.05) body weights at the finisher phase than the other treatment groups. The feed conversion ratio of TVS broilers was comparable to the TV group but lower ( < 0.05) than the other treatments. Reduced levels ( < 0.05) of heterophil, lymphocytes and hetrophil and lymphocyte ratio were recorded in the TVS compared to TV, TS and TC broilers. On day 42, the rectal temperature was significantly higher in CC than those in other treatment groups, which were comparable. TVS birds had higher ( < 0.05) weights of spleen, liver and lower abdominal fat than other treatments. The lowest concentration of plasma malondialdehyde and the highest activity of superoxide dismutase and glutathione peroxidase were recorded in TV and TVS birds. The study concluded that the growth performance and oxidative status in broilers were improved by the combination of EATC with supplemental Se and vitamin E (TVS).
热应激已被列为全球养鸡户面临的一个关键环境问题，因为它对禽类的生长、性能和健康有不利影响。本研究评估了早期热管理（EATC）和补充抗氧化剂对热带环境中肉鸡生理反应的影响。总共 300 只 1 日龄罗斯肉鸡雏鸡被分配到五个热和饮食处理，每个处理有 5 个重复，每个重复 12 只鸡。处理方式如下：采用常规方法饲养的雏鸡（CC）、5 日龄时暴露于 38°C 早期热环境中且不补充抗氧化剂的雏鸡（TC）、TC 加 250mg/kg 饲料的维生素 E（TV）、TC 加 0.5mg/kg 饲料的硒（TS）以及 TS 和 TV 的组合（TVS）。试验采用完全随机设计，SAS（2008）软件分析收集的数据。结果表明，TVS 组肉鸡在育肥后期的体重显著高于其他处理组（ < 0.05）。TVS 组肉鸡的饲料转化率与 TV 组相当，但低于其他处理组（ < 0.05）。与 TV、TS 和 TC 组相比，TVS 组肉鸡的异嗜细胞、淋巴细胞和异嗜细胞与淋巴细胞比值降低（ < 0.05）。CC 组肉鸡的直肠温度在第 42 天显著高于其他处理组，而其他处理组之间的直肠温度相当。TVS 组肉鸡的脾脏、肝脏重量较高，下腹部脂肪较低，与其他处理组相比有显著差异（ < 0.05）。TV 和 TVS 组肉鸡的血浆丙二醛浓度最低，超氧化物歧化酶和谷胱甘肽过氧化物酶活性最高。研究结论认为，EATC 与补充硒和维生素 E（TVS）的结合可提高肉鸡的生长性能和氧化状态。
