Comparative evaluation of dietary protein levels and plant-animal protein ratios inMacrobrachium rosenbergii(de Man)

Abstract

The effects of varying dietary protein level (200, 250, 300 and 350 g protein kg−1 diet) and plant : animal protein ratio (1 : 2, 1 : 1, 1 : 1.5 and 2 : 1) on growth of juvenile Macrobrachium rosenbergii (de Man) with approximately 0.27 g initial body weight were evaluated in two separate 30-days study using practical diets. Significantly lower survival rate was recorded in prawns fed a diet containing 200 g kg−1 dietary protein (66.67%) whilst 300 and 350 g kg−1 protein gave the highest survival (96.67%). Significant differences (P 0.05) in the specific growth rate, protein efficiency ratio, weight gain and survival rate among the juveniles of M. rosenbergii fed varying plant–animal protein ratios at 300 g kg−1 protein. Better-feed conversion ratio was recorded in diets having a plant to animal protein ratio of 1 : 1 (2.62) followed by 1 : 1.5 (2.66), however there was no significant difference between them (P > 0.05). Based on the present study, it would be possible to replace animal protein by low-cost plant protein in prawn feed. Better growth performance in juveniles of M. rosenbergii can be achieved by the incorporation of equal proportions of plant and animal protein (A : P = 1) in the diet.