Dietary optimisation of black gram (Vigna mungo) leaf meal as substitute for deoiled rice bran in the diet of Labeo rohita (Hamilton, 1822) fingerlings

Abstract

The study aimed to evaluate the potential of black gram (Vigna mungo) leaf meal (BGLM) as a substitutet for deoiled rice bran (DORB) in the diet of Labeo rohita (Hamilton, 1822) fingerlings. Four isonitrogenous (30% CP) and isocaloric (420 Kcal 100 g-1 gross energy) experimental diets were prepared to conduct the study with different inclusion levels of BGLM viz., control (0 BGLM; 30% DORB), LM10 (10% BGLM, 20% DORB), LM20 (20% BGLM, 10% DORB) and LM30 (30% BGLM, 0% DORB). One hundred forty-four fishes with an initial mean weight of 3.52±0.04 g were arbitrarily assigned to the indoor experimental tubs in triplicates for the 60 days experiment. Fish were fed with experimental diets to satiation twice daily. Percent weight gain and specific growth rate (SGR) were significantly (p<0.05) higher in LM20 group than the other treatment groups (LM10 and LM30) showing no significant (p>0.05) difference with the control group. Among the digestive and metabolic enzyme activities, lipase, hepatic aspartate amino transferase (AST) and alanine amino transferase (ALT) levels were found to be higher in LM20 group compared to the other groups. The study concluded that BGLM can completely replace DORB in the diet of L. rohita. However, the best growth and metabolic performance can be achieved with the inclusion of 20% leaf meal.

Keywords: Anti-nutritional factor, Deoiled rice bran, Labeo rohita, Leaf meal, Vigna mungo