This study was conducted to investigate the impacts of potassium diformate (KDF) on growth performance, fillet quality, plasma indices, immune response and intestinal morphology of juvenile Trachinotus ovatus. Six diets with 0 (KDF1), 3.00 (KDF2), 6.00 (KDF3), 9.00 (KDF4), 12.00 (KDF5) and 15.00 (KDF6) g/kg KDF were formulated to feed T. ovatus (average fish weight: 5.87 ± 0.03 g) for 8 weeks. The results indicated that 3.00 g/kg and 6.00 g/kg KDF significantly increased the growth parameters of juvenile T. ovatus (P < 0.05), whereas 6.00 g/kg and 9.00 g/kg KDF significantly reduced feed conversion ratio (P < 0.05). KDF level presented a significant improvement on fillet quality of juvenile T. ovatus (P < 0.05). With the increasing levels of KDF, triglyceride and glucose of plasma significantly declined (P < 0.05), whereas high density lipoprotein cholesterol significantly increased (P < 0.05). 6.00 g/kg dietary KDF significantly up-regulated mRNA levels of Nrf2, CAT, CuZn-SOD, MnSOD (P < 0.05) and increased antioxidative enzyme activities in liver (P < 0.05). Furthermore, 6.00 g/kg KDF supplementation significantly enhanced immune function of juvenile golden pompano by regulating the expression levels of hepatic NF-κB, TGF-β, ZO-1, Occludin and Claudin-3a (P < 0.05). 6.00 g/kg KDF significantly improved intestinal morphology compared with KDF1 diets (the control) (P < 0.05). In conclusion, the supplement of dietary KDF was beneficial for T. ovatus by promoting growth performance, improving fillet quality and intestinal morphology and enhancing immune response. The optimum supplement level of KDF in T. ovatus diet was 6.58 g/kg based on WGR.

本研究旨在调查二甲酸钾 (KDF) 对卵形鲻鱼幼鱼生长性能、鱼片质量、血浆指数、免疫反应和肠道形态的影响。配制了 0 (KDF1)、3.00 (KDF2)、6.00 (KDF3)、9.00 (KDF4)、12.00 (KDF5) 和 15.00 (KDF6) g/kg KDF 的 6 种日粮来喂养T. ovatus（平均鱼重：5.87 ± 0.03 g) 8 周。结果表明，3.00 g/kg 和 6.00 g/kg KDF 显着提高了卵鲽幼鱼的生长参数（ P <  0.05），而 6.00 g/kg 和 9.00 g/kg KDF 显着降低了饲料转化率（P  < 0.05 ） ）。KDF水平显着提高了幼鱼的鱼片质量T. ovatus ( P  < 0.05)。随着KDF水平的升高，血浆甘油三酯和葡萄糖显着下降（P  < 0.05），而高密度脂蛋白胆固醇显着升高（P  < 0.05）。6.00 g/kg 日粮 KDF 显着上调 Nrf2、CAT、CuZn-SOD、MnSOD 的 mRNA 水平（P  < 0.05），并增加肝脏的抗氧化酶活性（P  < 0.05）。此外，添加 6.00 g/kg KDF 通过调节肝脏 NF-κB、TGF-β、ZO-1、Occludin 和 Claudin-3a 的表达水平显着增强金鲳幼鱼的免疫功能（P < 0.05)。与 KDF1 日粮（对照）相比，6.00 g/kg KDF 显着改善了肠道形态（P  < 0.05）。总之，膳食中 KDF 的补充对T有益。卵形鱼通过促进生长性能、改善鱼片质量和肠道形态以及增强免疫反应。T中 KDF 的最佳补充水平。根据 WGR，卵形日粮为 6.58 g/kg 。