Is sodium diformate a beneficial feed supplement for European seabass (Dicentrarchus labrax)? Effect on growth performance and health status

The effect of dietary organic salt, sodium diformate (NDF), supplementation on growth performance and health status of European seabass (ESB, Dicentrarchus labrax) was investigated. Twelve groups of fish (IBW, 4.75 ± 0.04 g) were fed 4 diets supplemented with: 0, 0.3, 0.4 and 0.5% NDF (assigned as: CTRL, NDF3, NDF4 and NDF5 respectively) for 13 weeks. Results showed a prominent growth promoting effect for the 0.3% NDF diet, which resulted in the highest gain in weight, specific growth rate and feed utilization indices (P < .05) among all treatments. Growth and feed utilization of NDF3 and NDF4 fish groups were significantly improved, whilst those of NDF5 fish were not lower than the respective of control fish. NDF3-fed fish showed significant (P < .05) elevation in leucocytes count, lymphocyte and monocyte percentages, leucocytes phagocytosis (by >3 folds), serum proteins (by 31%) and lysozyme activity (by 13%) in comparison to the controls. Major nutrients and amino acids composition were not significantly (P > .05) altered by diet. These findings suggest the supplementation of 3 g NDF/kg diet as a potent growth and a basal health-promoter for European seabass juveniles.