Effects of varying levels of dietary vitamin E (α‐tocopherol) on growth performance, proximate and fatty acid composition of juvenile silver pomfret ( Pampus argenteus Euphrasen, 1788)

Summary This study investigated the effects of elevated dietary levels of vitamin E ( α ‐tocopherol) on growth performance, proximate composition and fatty acid profiles of juvenile silver pomfret, Pampus argenteus . Three semi‐purified experimental diets were formulated to contain 49% protein and 16% lipid. High docosahexaenoic acid ( DHA ) tuna oil was added to the diets to supplement DHA . A graded level of vitamin E (0‐, 50‐, and 100 mg kg −1 ) was added to experimental diets 1 to 3, respectively. Analyzed vit. E levels were 155.2, 195.3 and 236.4 mg kg −1 in diets 1, 2 and 3, respectively. The experiment was conducted for 12 weeks with juvenile silver pomfret (29.6 ± 7.6 g) using a flow‐through system consisting of nine 1‐m 3 tanks. Each treatment had three replicates and fish were stocked at the rate of 20 m −3 . Growth performance and feed utilization parameters of fish fed diets 2 and 3 were significantly (P < 0.05) higher than in fish fed diet 1, but the parameters in diets 2 and 3 did not differ significantly (P > 0.05). Although whole body protein levels were not influenced by the dietary vit. E levels, whole body lipid in fish fed diet 2 was significantly higher than in fish fed the other diets. The whole body vit. E levels in fish fed diet 2 (22.6 mg kg −1 ) and diet 3 (24.1 mg kg −1 ) were significantly (P < 0.05) higher than in those fed diet 1 (18.2 mg kg −1 ). Whole body total saturated fatty acids were significantly lower, and DHA levels higher in fish fed diets 2 and 3 than those fed diet 1. The results of the present study suggest that increasing dietary supplementation of vit. E in high lipid diets enhances the growth performance of fish and that a dietary level of 196 mg kg −1 vit. E is suitable for the growth of silver pomfret.