Influence of dietary Plukenetia conophora seed on growth performance, hepatic antioxidant status, blood chemistry, fillet quality, fatty acid, and oxidative stability of Clarias gariepinus

This study assessed the effects of dietary supplementation of Plukenetia conophora seed (PCS) on growth performance, blood chemistry, hepatic antioxidant status, fillet fatty acids, and physicochemical properties of Clarias gariepinus. Two hundred and seventy post-juvenile Clarias gariepinus (14.2 ± 1.4 g, BW) were randomly assigned to either T1, a control diet without PCS; T2, diet containing 2.5% PCS; or T3, diet containing 5% PCS, and were fed the different diets for 70 d. Each treatment consisted of six replicates with 15 fish per replicate. Diet had no effect (P > 0.05) on feed intake, hepatosomatic index, viscerosomatic index and survival rate of C. gariepinus. Body weight gain and specific growth rate increased (P < 0.05) as the level of PCS increased in diet. The T3 C. gariepinus had lower (P < 0.05) feed conversion ratio compared with the control C. gariepinus. Leucocytes, serum LDL-cholesterol and total cholesterol were higher (P < 0.05) in the control C. gariepinus compared with the T2 and T3 C. gariepinus. Hepatic glutathione peroxidase, superoxide dismutase, and catalase increased (P < 0.05) with increase in PCS levels in diet. Hepatic glutathione S-transferase was higher (P < 0.05) in the control C. gariepinus compared with the supplemented C. gariepinus. The percentage of C18:3n-3, C22:5n3 and C22:6n-3 was higher (P < 0.05) while that of C18:2n-6 and C20:4n-6 was lower (P < 0.05) in the fillet of C. gariepinus fed on 2.5% and 5% PCS compared with the control C. gariepinus. Dietary PCS had no effect on fillet pH, chemical composition, carbonyl concentration, water holding capacity, color coordinates, and TBARS values in C. gariepinus. These results evince that dietary inclusion of PCS enhanced fillet n-3 polyunsaturated fatty acids and growth performance without instigating fillet oxidative spoilage in C. gariepinus.