Effect of dietary protein level on excretion of ammonia in Indian major carp, Labeo rohita , fingerlings

Abstract

The study was conducted to investigate the effect of dietary protein on nitrogenous excretion in the form of ammonia in Indian major carp, Labeo rohita (Ham.), fingerlings (3.0 ± 0.25 g). Fish were fed to satiation in a metabolism chamber. Approximately isoenergetic diets containing 230, 280, 330 and 380 g kg−1 protein were used at 28°C. Ammonia-N excretory energy (U) as a percentage of ingested food energy (C) increased with an increase in dietary protein level: from 4.3% in fish fed 230 g kg−1 to 6.0% in fish fed 380 g kg−1 dietary protein. The relationship between excretory energy and dietary protein level is modelled.