Nutrient digestibility and intestinal enzyme activity of Clarias batrachus(Linn.) juveniles fed on dried fish and chicken viscera incorporated diets

A feeding trial was conducted for 56 days to study the effect of replacemen t of fish meal by dried fish and chicken viscera, and a combination of oil cakes, in the diet of Clarias batrachus juveniles. The nutritional values o f these by-products were studied through a digestibility experiment. No sig nificant difference in nutrient digestibility was observed in different die ts. Even 19.59% lipid in the diet of catfish did not affect the nutrient di gestibility. Both amylolytic and proteolytic enzymes in the intestine of ju veniles were studied. A decreased protease activity due to replacement of a nimal protein by plant protein and a decreased (P < 0.01) aspartate aminotr ansferase (ASAT) activity could be observed after inclusion of 22% of dried fish viscera in the diet of the catfish. Though body lipid content increas ed in fish fed a high level of lipid, fat-free body composition did not var y among the fish fed on different diets. (C) 1999 Elsevier Science Ltd. All rights reserved.