Lack of compensatory growth response in gilthead seabream ( Sparus aurata) juveniles following starvation and subsequent refeeding

Abstract

This study assessed the effect of short (one or two weeks) feed deprivation periods on compensatory growth response of gilthead seabream juveniles. A 10 weeks growth trial was performed and three different feeding protocols were tested: control group (C) fed to apparent satiation twice a day, 6 days a week, during the whole experimental period; one week or two weeks unfed groups (groups U1 and U2, respectively) and re-fed for the rest 8 weeks of the trial as the control group. Each feeding protocol was tested in triplicate groups of fish with an initial body weight of 58 g. Starvation for one or two weeks induced significant losses of body weight that, comparatively to the control group, totaled 18.5 and 30.5% for U1 and U2 group, respectively. An intense mobilization of liver lipid and glycogen was observed after 1 or 2 weeks of starvation while perivisceral lipids, eviscerated-body lipids and energy contents were only decreased in fish unfed for 2 weeks. During the subsequent re-feeding period no recovery of body weight lost was noticed in the previously unfed groups, and feed intake and feed efficiency were identical in all groups. No differences between slopes of growth trajectory between the control and unfed groups were noticed, indicating no convergence of growth of unfed groups towards that of control group. A total recovery of the whole-body composition, organ indices, liver and viscera composition was observed at the end of the trial. Overall, gilthead seabream juveniles were not able to compensate growth after the feed starvation imposed. Therefore, it can be concluded, that under the experimental conditions applied short – one or two weeks – feed restriction periods are not advisable as management strategy to be used in gilthead seabream production.