Replacement of by-catch fishmeal with dried chicken viscera meal in extruded feeds: effect on growth, nutrient utilisation and carcass composition of catfish Clarias batrachus (Linn.) fingerlings

An 84-day feeding trial was conducted to study the effect of replacing dietary fishmeal with dried chicken viscera meal (CVM) on the growth (net biomass gain, specific growth rate, SGR), feed acceptability, feed conversion ratio (FCR), protein efficiency ratio (PER) and carcass composition of Clarias batrachus fingerlings. Triplicate groups of fingerlings with mean initial body weight of 13.35 g were fed on six iso-nitrogenous and iso-lipidic diets. The control diet (CVM0) used marine by-catch fishmeal as the sole source of animal protein. In the other five diets (CVM100-CVM500), 20-100% of fishmeal was substituted by dried CVM at 20% increments. The highest body weight gain, SGR and PER, and the lowest FCR were observed in fish fed a diet containing 300-500 g CVM kg(-1). The fish accumulated increasing quantities of lipids and decreasing levels of ash in their carcasses with increasing levels of dietary CVM.