EN
The study was aimed at determining effects of feed ration on growth, within-group variability, and chemical composition of the body of juvenile zander (c. 25 g initial individual weight) grown out in a recirculation system for 42 days. The fish were fed a commercial pelleted trout feed offered at three rations (Group L: 1.2% of stock biomass; Group M: 1.6% of stock biomass; and Group H: 2.0% of stock biomass). Each experimental treatment involved two replicates. The feed rations used were found to significantly (p < 0.01) affect fish growth: the mean body weight on termination of the experiment was 47.9, 60.3, and 69.4 g in Group L, M, and H, respectively. Statistically significant differences were revealed also in SGR and fish condition. The most favourable food conversion ratio (FCR) and protein efficiency ratio (PER) were found in Group M, the between-group differences being significant as well (p < 0.05).