Antibiotics have been used in aquafeeds not only to mitigate infectious diseases, but also to boost growth performance. The rise of antibiotic resistance is a growing problem for aquatic pathogens as much as for terrestrial livestock farming, so there is the need to find potential alternatives. Organic acids (OA) and botanicals are widely used in terrestrial animals and they gained an increasing interest also in aquaculture, but to the best of our knowledge available data in aquaculture are very limited. The aim of the study was to determine the effect of AviPlus®Aqua (Vetagro SpA), a blend of OA (sorbic and citric acid) and nature-identical compounds (NIC, thymol and vanillin), on European seabass (Dicentrarchus labrax L.) growth performance.
Four hundred and eighty European seabass specimens of an average weight of 62 g were randomly distributed into 12 tanks (40 fish per tank) at SPAROS Lda (Portugal). The following 4 diets were tested in triplicate tanks: 1) control (CTR), 2) AviPlus®Aqua 1000 ppm, 3) AviPlus®Aqua 1500 ppm and 4) AviPlus®Aqua 2000 ppm. Fish were fed for 71 days and zootechnical parameters (final body weight – FBW; feed conversion ratio – FCR; specific growth rate – SGR; protein efficiency ratio – PER; feed intake - FI) were measured after 29 and 71 days. Data were analyzed with one-way ANOVA.
After 29 days of feeding, growth performance was not affected by dietary treatments. At the end of the trial (day 71), fish fed with AviPlus®Aqua at 2000 ppm showed a higher FBW than those fed the other diets (P<0.05). FCR and SGR were improved in a dose-dependent manner (Fig. 1). AviPlus®Aqua 2000 ppm group showed a significantly higher PER compared to the other diets.
In conclusion, European seabass fed a diet supplemented with 2000 ppm AviPlus®Aqua showed a significant improvement of overall zootechnical performance criteria (FBW, SGR, FCR and PER), highlighting the potential of this feed additive as promoter of growth performance in seabass farming.