Effect of α-tocopherol supplementation on growth performance, antioxidant activity and nutrient digestibility of Labeo rohita (Hamilton 1822) fingerlings fed corn gluten meal-based diet

Abstract

A 70 days feeding trial was conducted to determine the effects of α-tocopherol (vitamin E) on the growth performance, antioxidant activity and nutrient digestibility of Labeo rohita (Hamilton 1822) fingerlings fed corn gluten meal based diet. Fingerlings (initial average weight: 6.35 g) were fed seven graded levels of α-tocopherol viz., 0, 100, 200, 300, 400, 500 and 600 mg kg-1. Triplicate tanks were used and each tank housed 15 fingerlings. Fish were fed at the rate of 5% of live wet weight. Collected data was subjected to one-way analysis of variance (ANOVA). Results showed that fingerlings fed with 200 mg kg-1 of α-tocopherol showed significantly (p<0.05) higher weight gain (32.73 g), weight gain% (261%) and suitable feed conversion ratio (2.49). Among other experimental and control diets, optimum apparent digestibility coefficient (ADC%) of crude protein (CP) (73%), ether extract (EE) (74%) and gross energy (GE) (63%) was noted in the fish fed 200 mg kg-1 diet. Minimum oxidation (%) (7.66%) was observed at 600 mg kg-1 predicting that the antioxidant activity increased in a dose-dependent manner. Keywords: α-tocopherol, Antioxidant activity, Aquaculture, Corn gluten meal, Growth