Effect of dietary protein and lipid levels and protein–energy ratio on growth indices, feed utilization and body composition of freshwater prawn, Macrobrachium rosenbergii (de Man 1879) post larvae

Abstract

A grow-out experiment was designed to determine the effect of different dietary protein, lipid levels and protein–energy (P:E) ratio on growth performance and feed utilization of the freshwater prawn, Macrobrachium rosenbergii post larvae (PL) culture in pond net enclosures (hapa, 3.75 m−3 each) for 12 weeks (84 days). The experimental treatments were assigned in triplicate. Six test diets were formulated to contain three different protein levels (300, 350 and 400 g kg−1 diet) and two lipid levels (100 and 140 g kg−1 diet) in a factorial manner (3 × 2) to provided six different dietary P:E ratio: 16, 17, 18, 19, 20 and 21 mg CP kJ−1 g−1). The result showed that the highest significant (P≤0.05) survival rate, growth indices and feed utilization were observed for M. rosenbergii PL fed a diet with a P:E ratio of 17 mg CP kJ−1 g1, whereas, the lowest value was recorded for prawns fed a diet with a P:E ratio of 20 mg CP kJ−1 g−1. Whole body contents of protein and lipid were highest (P≤0.05) when fed diets with 21 and 17 mg CP kJ−1 g−1 respectively. Concerning dietary protein levels, the highest (P≤0.05) values for survival and growth indices were observed for PL fed a diet containing 300 g kg−1 diet protein. The same trend was observed for PL fed a diet with 100 g kg−1 diet lipid level, irrespective of dietary protein levels. A diet containing 300 g kg−1 protein and 100 g kg−1 lipid with a dietary P:E ratio of 17 mg CP kJ g−1 is recommended to stimulate growth performance and nutrients utilization efficiency of M. rosenbergii PL.