Effect of dietary vitamin C on the growth and survival rate of rohu (Labeo rohita)

Abstract

The experiment was carried out to evaluate the effect of dietary vitamin C on the growth and survival rate of rohu (Labeo rohita) for a period of 49 days from 5 th April to 24 th May, 2016 in 12 experimental aquaria in Wet Laboratory of the Department of Aquaculture, Bangladesh Agricultural University, Mymensingh. Fingerlings of initial weight of 6.02±0.00 g was released at the same stocking density (12 fingerlings per aquaria). Four different treatments (T1, T2, T3 and T4) each with three replications were used having different amount of vitamin C, T1 (0 mg vitamin C/kg feed), T2 (200 mg vitamin C/kg feed), T3 (400 mg vitamin C/kg feed) and T4 (600 mg vitamin C/kg feed). All four diets having a constant inclusion level of the following ingredients: fish meal 40%, rice bran 25%, wheat bran 25%, molasses 5%, soybean oil 4% and vitamin and mineral premix 1%. Final weight (g), weight gain (g), percent weight gain (%), specific growth rate (%/day), and protein efficiency ratio, varied from 7.31±0.14 to 7.83±0.15, 1.29±0.14 to 1.8±0.15, 21.48±2.37 to 30.12±2.54, 0.52±0.22 to 1.21±0.17 and 0.46±0.42 to 0.60±0.04, respectively. Highest FCR (7.81±0.22) was found in T1 and the lowest FCR (5.78±0.36) was found in T4. The highest PER (0.60±0.04) was found in T4 and the lowest PER (0.46±0.42) was found in T1. The highest survival rate (63.89±4.81) was found in T4 and lowest survival rate (47.22±9.62) was found in T1. Best growth performance was found in T4 followed by T3, T2 and T1. The present research findings suggested that the best growth performance and survival rate of Labeo rohita was obtained from supplementation of 600 mg vitamin C per kg feed containing diet which could be chosen by the fish feed manufacturer and fish farmers.