Growth response and body composition of sharpsnout sea bream (Diplodus puntazzo) fed a high energy diet with different protein levels

Abstract

A study was undertaken to determine the effect of a high energy diet with two different protein levels on growth, feedefficiency and whole body composition of sharpsnout sea bream (Diplodus puntazzo). Two isoenergetic diets (24.1-24.7MJ Kg-1 dry weight) with two different protein levels (46.7 and 52.5% dry weight) were fed to satiety to duplicate groupsof 300 fish (initial body weight 27.7 ± 0.2 g) for 94 days. At the end of the experiment, the fish fed 52.5% protein showeda statistically higher (P Whole body composition was similar among treatments while the high energy level of the diets significantly modified lipidand moisture content in comparison with fish at the beginning of the experiment. Protein efficiency ratio (PER) and grossprotein efficiency (GPE) of fish fed 46.7% protein diet were statistically higher than those for the other diet. It may beconcluded that the diet with a lower protein level has given better protein utilization and a protein sparing effect but tendedto result in reduced weight gain and feed intake, when compared with diet containing higher protein levels.

Keywords

• Diplodus puntazzo, Sharpsnout sea bream, P/E ratio, High energy diet, Growth