Effect of Methionine and Selenium on Growth and Nutrient Performance of Rohu (Labeo rohita)

Methionine-selenium improve the growth of rohu

Abstract

The demand for fish is increasing due to its better nutritional profile. Labeo rohita, Hamilton (Rohu) is one of the major cultivable carps in India and it is important to enhance the production potential of this species. The effect of an essential amino acid (methionine, 0.5%) and mineral supplement (selenium, 0.5mg/kg) was studied to evaluate its efficacy on synergistic effect on growth performance of fish. Growth parameters of rohu were studied for 90 days in 4 separate groups – C (control with normal feed), T₁ (feed with methionine), T₂ (feed with selenium) and T₃ (feed with both methionine and selenium) with 3 replicates. Fish fry (average length of 25±2.46 mm; weight of 2±0.62 g) were stocked @ 20 per tank. Three test diets (T₁, T₂ and T₃) were formulated with 30% protein level. Significant differences were found among treatment groups (P<0.05) in growth parameters, proximate composition and liver enzyme activity. Among all groups, T₃ exhibited the best result with a food conversion ratio of 1.24±0.03, specific growth rate (%) of 2.95±0.019 and protein (%) of 17.18±0.02 followed by T₁ (FCR- 1.31±0.009; SGR- 2.75±0.014; Protein- 16.75±0.02), T₂ (FCR1.62±0.004; SGR- 2.46±0.024; Protein- 14.96±0.04) and C (FCR- 1.89±0.001; SGR- 2.07±0.021; Protein 12.37±0.04). Results of this experiment indicate that the best overall growth and feed utilization of rohu fingerlings were obtained for T₃ as both methionine and selenium supplementation worked conjointly.