Effects of dietary protein and energy levels on the growth, feed utilization and body composition of yellow fin seabream Acanthopagrus latus juvenile

A feeding trial was carried out where, three protein concentrations [45%, 55% and 65%, crude protein (CP)] was fed to yellow fin sea bream (Acanthopagrus latus) fingerlings at three dietary energy concentrations [20, 22and 24 Kj g-1 crude energy (CE)] ,to determine the protein and energy requirement for this species. Triplicate groups of 20 fish (average weight 12±.2g) was each stocked in 300-L fiberglass tanks and fed twice a day to apparent satiation. After 8 weeks, the survival was independent of the dietary treatments, but the average fish weight gain (AWG), specific growth rate (SGR), food conversion ratio(FCR) and feed efficiency ratio (FER) were significantly affected by dietary protein(P < 0.05). Protein retention (PR), Viscera somatic index (VSI) and intraperitoneal fat ratio (IPF) were affected by dietary energy level (P<0.05).Grass energy retention (GER) and Condition factor (K) were affected by both dietary protein and energy levels(P<0.05). daily feed intake (DFI) was not affected by dietary protein and energy concentrations( P>0.05). PER, PR, GER,VSI and IFR increased with the increase of energy from 20 to 24 Kj g-1 at the same protein level. Carcass moisture, fat and ash contents were affected by dietary protein and energy levels( P<0.05). Carcass energy content increased with increasing dietary energy, but carcass moisture was decreased with increasing dietary energy from 20 to 24 Kj g-1.. It was concluded that the optimum dietary protein and energy level for growth of juvenile yellow fin sea bream maybe 562-574.7 g kg-1diet and 21.9- 24.56 Kj g-1 respectively.

Iranian Fisheries Science Research Institute

Published