Utilization of protein by fingerlings of a threatened freshwater catfish Mystus montanus

Abstract

A feeding trial was made to evaluate the utilization of protein as a dietary energy source by the fingerlings of the threatened freshwater catfish Mystus montanus. Six different diets were formulated from semi-purified ingredients with six different levels of proteins (6.97, 24.77, 30.70, 36.64, 42.57 and 46.72%) and were fed to replicate groups at 5% body weight daily for seven weeks. Based on the Specific Growth Rate (SGR), Food Conversion Ratio (FCR) and Protein Efficiency Ratio (PER), it was found that M. montanus fingerlings utilized proteins better than lipids and carbohydrates. At 30.70% protein level with a 2.31 kcal/g energy value to protein ratio of 7.52 mg/kcal the SGR and PER were significantly improved. However, lower SGR levels were obtained with diets containing very high levels of protein. An optimal protein level of 31% could be effectively utilized with no adverse effect by the threatened freshwater catfish M. montanus.