Brown fish meal substituting white fish meal affects growth performance, antioxidant capacity, immune response and flesh quality of mandarin fish (Siniperca chuatsi)

This experiment investigated the effects of substituting white fish meal (WFM) with brown fish meal (BFM) in the diet on growth performance, body composition, antioxidant capacity, immune response and flesh quality of mandarin fish. Six isonitrogenous and isolipidic diets, designated as WM60, WM48, WM36, WM24, WM12, and WM0 based on the quantity of white fish meal, were formulated with 0.00 %, 18.60 %, 37.87 %, 57.83 %, 78.53 %, and 100 % white fish meal substituted by brown fish meal, respectively. A total of five hundred and forty fish (20.99 ± 0.02 g) were randomly allocated into six experimental groups, with three replicate tanks per group. The results demonstrated that fish in the WM12 and WM0 groups had significantly higher final body weights and specific growth rates than those in the WM60 group. Moreover, the substitution of WFM by BFM significantly decreased the antioxidant capability, such as the increasing amount of malondialdehyde and the decreasing activities of total superoxide dismutase and catalase. At the transcriptional levels, the expression of superoxide dismutase 1 ( sod1 ), catalase ( cat ) and nuclear factor erythroid derived 2 ( nrf2 ) all significantly decreased with the increase level of dietary BFM substitution. Moreover, with the increase level of BFM substitution, the lysozyme activity showed a decrease trend and the expressions of mitogen-activated protein kinase 13 ( mapk13 ) mitogen-activated protein kinase 14 ( mapk14 ), nuclear factor-kappa B p65 ( rela ), interleukin-8 ( il8 ) and interleukin-1 beta ( il1β ) showed an upregulated trend. Additionally, as BFM substitution level increased, the hardness, adhesiveness, springiness, and shear force all decreased significantly. In conclusion, the substitution of WFM with BFM significantly improved the growth performance, feed utilization and muscle texture of mandarin fish, while produced negative effects on the antioxidant capacity and inflammation. Based on the comprehensive analysis of all results, with 60 % dietary WFM supplementation, 57.83∼78.53 % of WFM could be substituted by BFM. • Replacing white fish meal with brown fish meal could improve the growth performance of mandarin fish. • Brown fish meal substitution negatively affected the antioxidant capacity and immunity of mandarin fish. • Brown fish meal substitution affected the flesh quality of mandarin fish.