عنوان مقاله [English]
Administration of commercial antibiotics for disease treatment lead to undesirable effects and looking for proper alternatives seems essential in aquaculture. In this study, the effects of oral administration of Ergosan and Levamisolewamin on hematological and immunological indices of rainbow trout Oncorhynchus mykiss were investigated. 450 juvenile rainbow trout randomly divided in three groups, each in triplicates. First group fed with food supplemented with Levamisole, second group fed with Ergosan supplemented food, but control group fed with unsupplemented food. All groups fed with experimental diet for 60 days. Biometric assay were conducted in 0, 30 and 60 days of study and growth indices (SGR, FCR, CF, WGP and PER) calculated after 30 and 60 days. At the end of treatment blood samples were taken from fish in each treatment and haematological (PCV, Hb, RBC, WBC, MCV, MVH and MCHC) and immunological (Lysozym and bactericidal activity) factors were compared among groups. Results showed that almost all growth indices were increased in both Ergosan and Levamisol groups compare to control group (P<0.05), but no significant difference observed between Ergosan and Levamizol groups (P>0.05). Lysozyme activity increased significantly in Levamizol group (P<0.05), but no significant extent in Ergosan and Levamisol groups compare to control (P>0.05). Haematological parameters of fish in all groups showed no significant change after 60 days of feeding with experimental diets (P>0.05). It can be concluded that Ergosan and Levamizol can stimulate growth and immunological indices of rainbow trout Oncorhynchus mykiss, without any side effects on haematological factors, so they can be used as growth and immune stimulators in trout culture.