Correction to: The effect of a phytogenic feed additive (Digestrom P.E.P) on growth performance, proximate composition, hematological and immunological indices of juvenile beluga sturgeon Huso huso

A 10-week trial was undertaken to evaluate the effects of a phytogenic feed additive (Digestrom P.E.P) on growth, proximate chemical composition, hematological, and immunological indices of juvenile beluga sturgeon Huso huso (159.5 ± 0.2 g initial weight). Twelve 800 L tanks were stocked with 15 fish in each, with three tanks being used for each feed treatment. The fish were fed to satiation (4 meals day −1 ) for 70 days, during which time they were given either a control feed (40.7% protein, 16.1% fat, 12.5% moisture, and 9.1% ash) without Digestrom P.E.P (diet 0) or a feed containing 10, 20, or 40 g kg −1 Digestrom P.E.P. After 70 days, a significantly higher ( p < .05) final individual weight was recorded for fish given the feed with 20 g kg −1 Digestrom P.E.P (ca 435 g) than for fish given the other feeds (range ca 397–417 g). There were no significant effects on feed intake, feed conversion ratio, fish condition factor, and survival rate ( p > .05). Fish given the feed with 20 g kg −1 Digestrom P.E.P had significantly higher carcass crude protein (ca 18.9%) than fish provided with the other feeds (carcass protein range ca 14.8–17.8%), but there were no significant effects on carcass fat, ash, and moisture contents. Moreover, no changes were observed in the number of red blood cells, hemoglobin, hematocrit value, mean corpuscular volume, mean corpuscular hemoglobin concentration, lymphocytes, monocytes, and eosinophils among the treatments ( p > .05). We observed the highest number of white blood cells (11.5 ± 0.1 × 10 3 mm −3 ) and neutrophils (31.0 ± 0.8%) in fish fed with 20 g kg −1 Digestrom P.E.P. Furthermore, among the non-specific parameters, fish fed with 10 and 20 g kg −1 Digestrom P.E.P had the highest lysozyme activity compared to other treatments ( p < .05). Based on the results, we can conclude that Digestrom P.E.P at the level of 20 g kg −1 as an immunostimulant in the diet of juvenile beluga sturgeon can enhance growth performance and innate immune system.