The effects of different cycles of starvation and refeeding on growth and body composition on European sea bass (Dicentrarchus labrax)

This study was designed to investigate the effects of starvation and re-feeding cycles on growth performance and body chemical composition of sea bass juveniles. For this purpose, a total of 720 juveniles with initial mean weight (IW) of 5.85±0.54 g were stored in tanks (400 L) as triplicate groups. In the experiment, four different feeding regimes with cycles were applied to fish groups for 50 days. During the period of trial, control group (G1) was fed to satiation three times a day. The feeding regimes of the other three groups were designed as follows: 2 days starvation/8 days satiation (G2) (5 cycles), 5 days starvation/20 days satiation (G3) (2 cycles) and 10 days starvation/40 days satiation (G4) (1 cycle). During study, fish sampling was made every 10 days and parameters including nutrient composition, growth rates, feed utilization, Total Fat (TF) ratio and Hepato Somatic Index (HSI) were determined by taking 5 fish from each tank. At the end of the study, only G2 group demonstrated partial compensatory growth and the difference between the Final Weights (FW) of groups was found statistically significant (p<0.05). Specific Growth Rates (SGR) and Daily Growth Rates (DGR) of fasting groups were found lower than those of control group (p<0.05). G4 groups was determined to have the best values of Feed Conversion Ratio (FCR) and Economic Conversion Ratio (ECR), and a statistically significant difference was detected between FCR values of all groups (p<0.05). HSI did not demonstrate a significant difference between groups (p>0.05), while TF ratio was found lowest in G4 (p<0.05). Whole-body lipid compositions of fish were affected by feeding regime. According to data obtained in the study, G2 group demonstrating partial compensation is suggested for economic evaluation.