Effects of dietary vitamin E on growth performance, body composition, antioxidant capacity, and some immune responses in Caspian trout (Salmo caspius)

This study was conducted to evaluate the effect of dietary vitamin E on growth performance, feed utilization, biochemical properties and some immune responses in Caspian trout, Salmo caspius. Six experimental diets were formulated with semi-purified ingredients supplemented form DL-α-tocopherol acetate provide actual concentrations 4.9 (the basal diet), 8.6, 17.4, 35.4, 78.8 137.0 mg kg−1 diet, respectively. Each diet assigned three replicate groups trout (initial average weight 9.73 ± 0.34 g) for eight weeks. Weight gain ratio (WGR), specific rate (SGR), protein efficiency (PER) found be significantly enhanced by increasing level reached highest values fish fed (P < 0.05). A linear trend recorded crude protein, fat content, superoxide dismutase (SOD) activity, liver concentration, immunoglobulin M (IgM), alternative complement activity (ACH50), while glutathione peroxidase (GPX) linearly quadratically response supplementations There also decreasing alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine (ALT) activities as well serum glucose (GLC) malondialdehyde (MDA) levels supplementing Analysis polynomial regression SGR, GLC, SOD against varying revealed that optimum requirements 79.44, 78.73, 82.16 kg−1,