Effects of previous ration restriction on compensatory growth in barramundi Lates calcarifer

Compensatory growth of juvenile barramundi Lates calcarifer was examined after fish had experienced different pre-feeding regimes. Fish were first fed at 0%, 25%, 50% and 75% satiation (RL0, RL25, RL50 and RL75, respectively) for 2 weeks before satiation feeding was imposed for the next 5 weeks. The control fish were fed to satiation throughout the whole experimental period. Changes in body weight, specific growth rate, feeding rate, feed conversion efficiency and apparent digestibility coefficient were measured weekly after satiation feeding was imposed. Fish body chemical composition was determined in weeks 2 and 7, respectively. The results showed that fish previously fed at 50% and 75% satiation caught up with the control fish weight in 2 and 4 weeks, respectively, after the start of satiation feeding. It showed that a complete compensatory response occurred in these fish. However, fish fed at 0% and 25% satiation did not catch up with the control fish weight at the end of the experimental period. Hyperphagia. was observed in all feed-restricted fish in the first week of satiation feeding. However, no hyperphagia was found in any feed-restricted fish in the third week of satiation feeding. Although hyperphagia reoccurred in RL0 fish in week 6 and in RL25 fish in week 7, their final weight did not reach that of the control fish. Prior to satiation feeding in week 3, body lipid, energy, moisture contents and lipid/lean body mass (LBM) ratio in fish fed at <50% satiation were significantly less than those in the control. Body protein in fish completely deprived of feed was less than that of the control, while the ash content in these fish was more than that in the control. It can be concluded that a moderate feed restriction (50-75% satiation) for 2 weeks resulted in complete compensatory growth, while a severe feed restriction (0-25% satiation) for 2 weeks did not lead to complete compensatory growth in barramundi. (C) 2004 Elsevier B.V. All rights reserved.