The experimental diets containing five levels of creatine supplementation, namely control (N = 0 g/kg creatine), B1 (1.00 g/kg glycine), B2 (0.40 g/kg creatine), B3 (0.80 g/kg creatine) and B4 (1.20 g/kg creatine) were tested to red tilapia up to apparent satiation 3 times a day for 56 days. After the feeding trial, fish were stressed by air exposure for challenge test against stress. The results described that creatine supplementation improved final body weight, feed conversion ratio (FCR) and protein retention. Creatine supplementation decreased blood glucose, cholesterol and triglyceride levels (p < .05), indicating more effective usage of non‐protein energy. Furthermore, creatine supplementation also increased plasma insulin levels and upregulated IGF‐1 and GLUT4 gene expressions in the liver significantly; it also improved robustness against stress, which was shown by higher superoxide dismutase, higher postchallenge survival and plasma cortisol, malondialdehyde and lower glucose levels. In conclusion, creatine supplementation at a dose of 0.289–0.389 g/kg diet escalated fish growth and improved robustness against stress via improving the SOD activity in red tilapia.

中文翻译：

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含分级肌酸的日粮罗非鱼（Oreochromis sp。）的生长性能，抗逆性，血清胰岛素，IGF-1和GLUT4基因表达

实验饮食包含五种肌酸补充水平，即对照（N  = 0 g / kg肌酸），B1（1.00 g / kg甘氨酸），B2（0.40 g / kg肌酸），B3（0.80 g / kg肌酸）和B4每天3次（1.20 g / kg肌酸）检测红色罗非鱼至饱足感，共持续56天。喂食试验后，将鱼暴露在空气中进行应激测试以应对压力。结果表明补充肌酸改善了最终体重，饲料转化率（FCR）和蛋白质保留。补充肌酸可降低血糖，胆固醇和甘油三酸酯水平（p < .05），表明更有效地利用了非蛋白质能量。此外，补充肌酸还可以显着提高血浆胰岛素水平，并显着上调肝脏中的IGF-1和GLUT4基因表达。它还具有更高的抗氧化能力，表现为更高的超氧化物歧化酶，更高的挑战后存活率和血浆皮质醇，丙二醛和更低的葡萄糖水平。总之，以0.289–0.389 g / kg的日粮添加肌酸可提高红罗非鱼的SOD活性，从而促进鱼的生长并提高抗逆性。