Authors : Sudagar Mohamad and Hajibeglou Abasali
Abstract: Ten plants were extracted with 70% ethanol and screened for their antimicrobial activities against Aeromonas hydrophila, a bacterial pathogen. Using disk diffusion assays, five extracts among these ten (Inula helenium, Tussilago farfara, Brassica nigra, Echinacea purpurea and Chelidoniume majus) were selected and equal proportions of them were mixed thoroughly with the artificial feeds at concentrations of 0.0 (A), 100 (B), 250 (C), 500 (D), 750 (E) and 1000 (F) mg kg-1 of dry diet. The prepared diets were fed to healthy common carp (Cyprinus carpio) for 60 days and then challenged with A. hydrophila. To evaluate the immune response and resistance against A. hydrophila infection of fish, haematological, biochemical and immunological parameters of them were investigated at 20, 40 and 60 days of feeding and also 10th day post-challenge. Results indicated that respiratory burst activity, serum bactericidal activity, lysozyme, serum protein, albumin, globulin, WBC, RBC and haemoglobin content were enhanced (p<0.05) in fish fed herbal diets compared to the control group. On 10 days post-challenge, the total survival rates were 38.09% in control group (A) and 61.90, 67.62, 77.14, 85.71 and 80.95% in group B, C, D, E and F, respectively. Among different groups, E generally showed the best performance in the experiment. Further research is needed to isolate and characterize the active compounds from these plants.
Sudagar Mohamad and Hajibeglou Abasali, 2010. Effect of Plant Extracts Supplemented Diets on Immunity and Resistance to Aeromonas hydrophila in Common Carp (Cyprinus carpio). Agricultural Journal, 5: 119-127.