College of Animal Science and Technology, Key Laboratory of Animal Origin Food Production and Safety Guarantee of Jiangsu Province, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing 210095, China.
Institute of Agro-Product Processing, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
Poult Sci. 2023 Dec;102(12):103103. doi: 10.1016/j.psj.2023.103103. Epub 2023 Sep 15.
Chronic heat stress has detrimental effects on the growth performance of broilers, and the potential mechanism is under exploration. In this study, the protein carbonyl modification was introduced to glycolytic enzymes to evaluate its relationship with the growth performance of heat-stressed (HS) broilers. A total of 144 male 28-day-old broilers were assigned to 3 treatments: the normal control group (NC, raised at 22°C with free access to feed and water), the HS group (raised at 32°C with free access to feed and water), and the pair-fed group (PF, raised at 22°C with an amount of feed equal to that consumed by the HS group on a previous day). Results showed that heat stress decreased the average daily growth, increased the feed-to-gain ratio (F/G), decreased breast muscle rate, and increased abdominal fat rate compared with the NC and PF groups (P < 0.05). Higher cloacal temperature and serum creatine kinase activity were found in the HS group than those of the NC and PF groups (P < 0.05). Heat stress increased the contents of carbonyl, advanced glycation end-products, malonaldehyde, and the activities of catalase, glutathione peroxidase, and total antioxidant capacity compared with the NC and PF groups (P < 0.05). Heat stress increased the contents of glucose and lactate, declined the glycogen content, and lowered the relative protein expressions of pyruvate kinase muscle type, lactate dehydrogenase A type (LDHA), and citrate synthase compared to those of the NC group (P < 0.05). In contrast to the NC and PF groups, heat stress intensified the carbonylation levels of phosphoglucomutase 1, triosephosphate isomerase 1, β-enolase, and LDHA, which were positively correlated with the F/G (P < 0.05). These findings demonstrate that heat stress depresses growth performance on account of oxidative stress and glycolysis disorders. It further increases the carbonylation of glycolytic enzymes, which potentially correlates with the F/G by disturbing the mode of energy supply of broilers.
慢性热应激对肉鸡的生长性能有不利影响，其潜在机制正在探索中。本研究引入糖酵解酶的蛋白质羰基修饰来评估其与热应激（HS）肉鸡生长性能的关系。将 144 只 28 日龄雄性肉鸡随机分为 3 个处理组：正常对照组（NC，在 22°C 下饲养，自由采食和饮水）、热应激组（HS，在 32°C 下饲养，自由采食和饮水）和限饲组（PF，在 22°C 下饲养，饲料量与前一天 HS 组消耗的饲料量相等）。结果表明，与 NC 和 PF 组相比，热应激降低了平均日增重，增加了饲料增重比（F/G），降低了胸肌率，增加了腹脂率（P < 0.05）。HS 组的直肠温度和血清肌酸激酶活性高于 NC 和 PF 组（P < 0.05）。与 NC 和 PF 组相比，热应激组的羰基含量、晚期糖基化终产物、丙二醛、过氧化氢酶、谷胱甘肽过氧化物酶和总抗氧化能力的活性增加（P < 0.05）。与 NC 组相比，热应激组的葡萄糖和乳酸含量增加，糖原含量降低，丙酮酸激酶肌肉型（PKM）、乳酸脱氢酶 A 型（LDHA）和柠檬酸合酶的相对蛋白表达降低（P < 0.05）。与 NC 和 PF 组相比，热应激组磷酸葡萄糖变位酶 1、磷酸丙糖异构酶 1、烯醇化酶和 LDHA 的羰基化水平增强，与 F/G 呈正相关（P < 0.05）。这些发现表明，热应激通过氧化应激和糖酵解紊乱抑制生长性能，进一步增加糖酵解酶的羰基化，通过扰乱肉鸡的能量供应模式，可能与 F/G 相关。
