Culter alburnus is sensitive to stressors. Arginine is a precursor of nitric oxide, which can effectively relieve the level of oxidative stress and improve the antioxidant and immune capacity of fish. The effect of different arginine levels on topmouth culter (Culter alburnus) fry development performance, liver antioxidant capacity, and immune parameters were investigated in this study. Five diets (1.96%, ARG1, control group; 2.28%, ARG2; 2.52%, ARG3; 2.81%, ARG4; 3.09%, ARG5) were used to feed fry (initial weight 0.31 ± 0.01 g) for 8 weeks. The data showed that the final weight (FW), weight gain rate (WGR), and specific growth rate (SGR) of the ARG3 and ARG4 groups were significantly improved, while the feed conversion ratio (FCR) reduced significantly. Compared with the ARG1 group, all groups remarkably reduced the crude ash content of the whole body. The activity of hepatic superoxide dismutase (SOD) and the content of hepatic glutathione (GSH) were significantly increased in the ARG3 and ARG4 groups, while the malondialdehyde (MDA) content was significantly decreased. Compared with the ARG1 group, arginine levels in ARG2, ARG3, and ARG4 groups up-regulated the expression levels of Nrf2, down-regulated the gene expression level of Keap1 in the liver. And the expression of Nrf2/Keap1 pathway downstream genes Mn-SOD and CAT was up-regulated in ARG2 and ARG3 groups. Furthermore, the expression levels of MyD88 and IL-1β were down-regulated, and the anti-inflammatory gene TGF-β expression levels were up-regulated in the ARG2, ARG3, and ARG4 groups. Additionally, compared to the ARG1 group, there was a significant increase in the relative expression levels of the C3 and C4 genes in the ARG4 group. In conclusion, 2.28–2.81% dietary arginine levels improved the growth performance, promoted antioxidant capacity, and enhance immune response. The optimal level of arginine was determined by the quadratic regression analysis of SGR and FCR to be 2.55% of diet (5.43% of dietary protein) and 2.53% of diet (5.38% of dietary protein), accordingly.

翘嘴鲌对压力源很敏感。精氨酸是一氧化氮的前体，能有效缓解氧化应激水平，提高鱼类的抗氧化和免疫能力。本研究探讨了不同精氨酸水平对顶嘴鲌（ Culter alburnus）鱼苗发育性能、肝脏抗氧化能力和免疫参数的影响。使用五种饲料（1.96%，ARG1，对照组；2.28%，ARG2；2.52%，ARG3；2.81%，ARG4；3.09%，ARG5）喂养鱼苗（初始重量 0.31 ± 0.01 g）8 周。数据显示，ARG3和ARG4组的最终体重（FW）、增重率（WGR）和特定生长率（SGR）显着提高，而饲料转化率（FCR）显着降低。与ARG1组相比，各组全身粗灰分含量均显着降低。 ARG3和ARG4组肝超氧化物歧化酶（SOD）活性和肝谷胱甘肽（GSH）含量显着升高，丙二醛（MDA）含量显着降低。与ARG1组相比,ARG2、ARG3、ARG4组精氨酸水平上调肝脏Nrf2表达水平,下调Keap1基因表达水平。 ARG2和ARG3组Nrf2/Keap1通路下游基因Mn-SOD和CAT表达上调。此外，ARG2、ARG3和ARG4组中MyD88和IL-1β的表达水平下调，抗炎基因TGF-β的表达水平上调。此外，与ARG1组相比，ARG4组中C3和C4基因的相对表达水平显着增加。总之，2.28-2.81% 的日粮精氨酸水平可以改善生长性能，提高抗氧化能力，并增强免疫反应。通过SGR和FCR的二次回归分析确定精氨酸的最佳水平为日粮的2.55%（日粮蛋白质的5.43%）和日粮的2.53%（日粮蛋白质的5.38%）。