Effects of graded levels of dietary vitamin E on striped surubim Pseudoplatystoma reticulatum

Vitamin E is important to animal health, growth, productive performance, fillet quality and immune systems. This study evaluated the effects of dietary vitamin E on flesh composition, growth, biochemical and immunological parameters of striped surubim, Pseudoplatystoma reticulatum. Prior to beginning of the feeding trial, fish were fed a vitamin E‐free control diet for 45 days to reduce body deposits. The trial was set up in a completely randomized design; diets containing 3.4; 28.4; 53.4; 103.4; 153.4 and 303.4 mg DL‐α‐tocopherol acetate per kg of ration (n = 3) were fed twice a day to apparent satiation, for 90 days. Juvenile striped surubim (38.1 ± 4.9 g and 17.5 ± 1.5 cm) randomly stocked in 18 plastic tanks (300 L; 10 fish per tank). Based on serum globulin content and liver and fillet deposition of vitamin E, inclusion of 166.6 mg/kg of DL‐alpha tocopherol acetate in the diet is recommended to improve the immunological status and, probably, flesh quality of striped surubim.