Effect of dietary protein levels on growth, feed utilization and carcass composition of endangered bagrid catfish Horabagrus brachysoma (Gunther 1864) fingerlings

Abstract

An 84-day feeding trial was conducted to study the effect of different levels of dietary protein, 250 (P25), 300 (P30), 350 (P35), 400 (P40) and 450 g (P45) kg−1 dry matter (DM) on growth, feed intake, feed utilization and carcass composition of bagrid catfish Horabagrus brachysoma fingerlings. Triplicate groups of fingerlings with mean initial body weight of 2.2 g were fed the experimental diets twice daily, till satiation, in 150-L tanks supplied with flow-through freshwater. Daily dry matter intake by the fingerlings decreased significantly (P < 0.05) when fed P25 diet, containing 250 g protein kg−1. The highest body weight gain, specific growth rate (SGR) and protein efficiency ratio (PER), and the lowest feed conversion ratio (FCR) were observed in fish fed 350 g protein kg−1 diet. The fish fed with P45 diet had the lowest (P < 0.05) carcass lipid content. The polynomial regression analysis indicates that H. brachysoma fingerlings require 391 g dietary crude protein kg−1 diet.