Bioflocs are rich in a variety of probiotics and bioactive compounds, which have been documented to promote growth, regulate antioxidant status and enhance the immune system. A 60‐day experiment was conducted to investigate the effects on growth, antioxidant and immune status, NF‐κB/Nrf2 signalling molecules and stress resistance in juvenile Rhynchocypris lagowskii Dybowski fed different dietary biofloc supplementations. Four hundred fifty R. lagowskii were fed five experimental diets containing graded levels of biofloc from 0 to 160 g/kg (referred to as B0, B4, B8, B12 and B16, respectively). The results showed that biofloc supplementation markedly promoted growth performance (weight gain rate, specific growth rate); improved amylase, lipase and protease activity; and enhanced the activities of glutathione peroxidase, catalase, total superoxide dismutase, total antioxidant capacity, lysozyme, complement C3, complement C4 and immunoglobulin M in the gill, hepatopancreas, kidney, gut and serum. The malondialdehyde content was significantly reduced with treatment B12. In addition, the levels of heat shock protein 70, heat shock protein 90, interferon‐γ and insulin‐like growth factor I were substantially increased with treatment B12 compared to those with the control treatment. Furthermore, biofloc assisted in regulating the expression of NF‐κB/Nrf2 signalling molecule genes, including NF‐κB, TNF‐α, IL‐1β, IL‐8, IL‐10, TGF‐β, Nrf2, Keap1, Maf, HO‐1, CAT, GPX, GCLC and CuZn‐SOD. Overall, our results suggest that dietary supplementation with biofloc can promote growth, improve immune and antioxidant status, and enhance NF‐κB/Nrf2 signalling molecule expression and stress resistance in juvenile R. lagowskii. A suitable supplementation level of approximately 120 g/kg biofloc is recommended in the present study.

中文翻译：

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日粮中添加生物絮凝剂可促进生长，提高免疫和抗氧化状态，并上调NF-κB/ Nrf2信号分子和拉格氏丝藻的抗逆性

生物絮凝剂富含各种益生菌和生物活性化合物，据记载它们可促进生长，调节抗氧化剂状态并增强免疫系统。进行了为期60天的实验，研究了饲喂不同饮食生物絮凝剂的幼年Rhynchocypris lagowskii Dybowski对生长，抗氧化和免疫状态，NF-κB/ Nrf2信号分子和抗逆性的影响。四五R. lagowskii饲喂五种实验性日粮，它们的生物絮凝物含量为0至160 g / kg（分别称为B0，B4，B8，B12和B16）。结果表明，生物絮凝剂补充剂显着促进了生长性能（增重率，比生长率）；改善淀粉酶，脂肪酶和蛋白酶活性；并增强了ill，肝胰腺，肾脏，肠和血清中谷胱甘肽过氧化物酶，过氧化氢酶，总超氧化物歧化酶，总抗氧化能力，溶菌酶，补体C3，补体C4和免疫球蛋白M的活性。处理B12使丙二醛含量显着降低。此外，与对照组相比，B12处理组的热休克蛋白70，热休克蛋白90，干扰素γ和胰岛素样生长因子I的水平显着增加。此外，NF-κB，TNF-α，IL-1β，IL-8，IL-10，TGF-β，Nrf2，Keap1，Maf，HO-1，CAT，GPX，GCLC和CuZn-SOD。总的来说，我们的研究结果表明，膳食补充生物絮凝可以促进生长，提高免疫力和抗氧化状况，增强NF-κB/ Nrf2的信令少年分子表达和抗逆性R. lagowskii。在本研究中建议约120 g / kg生物絮凝剂的适当补充水平。