UTILISATION OF Hygrophila spinosa LEAF MEAL AS A REPLACER OF DE-OILED RICE BRAN IN THE DIET OF Labeo rohita (HAMILTON, 1822)

A 60-day feeding trial was conducted to optimise the dietary inclusion of Hygrophila spinosa leaf meal (HSLM) by replacing de-oiled rice bran (DORB) (30% inclusion) in the diet of Labeo rohita fingerlings based on growth performance, nutrient utilisation and physio-metabolic responses. Eight iso-nitrogenous (30% crude protein) and iso-caloric (300 Kcal DE/100g) practical diets were prepared with graded level of HSLM by replacing DORB viz- control (0% HSLM, 30% DORB), LM10 (10% HSLM, 20% DORB), LM20 (20% HSLM, 10% DORB ), LM30 (30% HSLM, 0% DORB), CEE (control diet with 0.1% of xylanase and cellulase), LM10EE (LM10 diet with 0.1% of xylanase and cellulase), LM20EE (LM20 diet with 0.1% of xylanase and cellulase) and LM30EE (LM30 diet with 0.1% of xylanase and cellulase). Two hundred and eighty eight fingerlings (average b.wt 3.52 ± 0.08 g) were randomly distributed in eight experimental groups in triplicates. Feeding of fish was done to satiation by using respective experimental diet throughout the experimental period. Highest (p < 0.05) growth performance (Fig 1), RNA content and RNA:DNA ratio were observed in LM10 and LM10EE group (10% HSLM containing diet with or without exogenous enzyme), while fish fed with 20% and 30% HSLM containing diets did not show any significant variation (p > 0.05) on growth performance with  control. Though amylase activity (Fig 2) was found to be significantly higher in fish of LM10, LM20, CEE, LM10EE and LM20EE groups, the fish of LM30 and LM30EE did not show any significant variation with control. Supplementation of exogenous enzymes significantly increased the muscle ALT and AST activities in LM10EE and LM20EE groups. Hence, it can be concluded that 100% replacement of DORB (30% inclusion level) is possible with HSLM without any detrimental effect for a period of 60 days. However, the combination of 10% HSLM and 20% DORB is better than DORB based diet (control).