Comparison the effects of some immunostimulants and medicinal plants extract on growth rate and resistance against environmental stressors in Barbus barbulus

Document Type : Research Paper

Abstract

    In this study the growth stimulatory effects and resistance against environmental stressors (density, transport and bacterial infection) of oral administration of Levamizol, Ergosan  and Vitamin C as well as extracts of Echinaeca, Aloe vera, viscum albom and Nigella sativa, in barbus barbulus were investigated. A total of 1200 fish (weighing 1.9±0.12 g) were randomly divided into 8 groups in triplicates for each immunostimulant plus to control group. The fish fed mixed with immunostimulants and each treatment was fed with their specific food for 6 weeks. Mortality rate during the study, initial and final weight and food consumption were recorded in each group. At the end of the study the density and transport stress tests were carried on and all treatments challenged with Aeromonas hydrophila. Results showed that growth factors including Specific growth rate, growth percentage and growth conversion rate significantly improved in all treatments except Nigella sativa compare to control (P<0.05). Post challenge mortality and density stress mortality significantly decreased in all treatments except Vitamin C and Nigella sativa groups compare to control (P<0.05). No significant changes were seen in mortality rate during treatment period and results of transport stress test (P>0.05). It can be concluded that the extracts of Echinacea purpurea and Viscum albom have stimulatory effects on growth and resistance against bacterial infection and density stress in Barbus barbulus and it is comparable with the effects of approved fish immunostimulants such as Ergosan, Levamizol and Vitamin C.

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