The Immunostimulatory Effects of Commercial Feed Additives on Growth Performance, Non-specific Immune Response, Antioxidants Assay, and Intestinal Morphometry of Nile tilapia, .

The main objective of the present research was to investigate the impacts of commercial immunostimulants on growth, non-specific immune response, antioxidant enzymes, and intestinal morphometry of Nile tilapia, . Fish (100 ± 6.5 g) were randomly divided into five groups in triplicates (150 fish in each replicate), stocked in 20 m of aerated concrete ponds. The fish were fed on a control diet (30.0% crude protein) (control), and four experimental diets supplemented with Yeast Plus, Digestarom, and Biotronic Top at 1 kg ton, and Sanolife PRO-F at 0.5 kg ton. After the experimental period, the highest significant yield (kg m), mean final weight (g fish), average weight gain (g fish), and specific growth rate (% body weight day), were recorded in fish fed on the diet supplemented by Sanolife PRO-F, followed by Yeast Plus ponds. The lowest yield was recorded in the control group. However, the feed conversion ratio was significantly decreased with Sanolife PRO-F diet. Furthermore, the hematological analysis increased in the following ascending order: Sanolife PRO-F; Yeast Plus; Biotronic Top3 and finally Digestarom groups. The lowest concentrations of white blood cells, red blood cells, hematocrite, and hemoglobin ( ≤ 0.05) were observed in the control group. The levels of phagocytic activity and phagocytic index were significantly higher in fish fed with Sanolife PRO-F group ( ≤ 0.05). Likewise, serum lysozyme activity was significantly highest in Sanolife PRO-F (0.63 and 0.68 U/mL, after 0.5 min and 3 min, respectively). Levels of total serum proteins, globulin, Immunoglobulin M, catalase, and super oxide dismutase were significantly higher in fish fed with Sanolife PRO-F supplement. On the contrary, length measurement of the intestinal villus height/width, absorption area, crypt depth, and goblet cells, were significantly lower in the control group, whereas their highest values was observed in fish fed Sanolife PRO-F ( ≤ 0.05). Consequently, Sanolife PRO-F is recommended at a level of 0.5 kg ton, to improve the growth performance, antioxidative capacity, and immune response of Nile tilapia.