Comparison of oral and parenteral injection administration of Echinacea purpurea on some immunological and hematological paramers of grass carp (Ctenopharyngodon idella)

Herbal immunostimulants have numerous potential benefits in comparison to vaccines and drugs like antibiotics in aquaculture.
In this study, effects of administration of Echinacea purpurea in oral and intra peritoneal routs on some hematological and immunological parameters of the grass carp (Ctenopharyngodon idella) were investigated.
A total of 240 healthy juvenile grass carp were randomly divided into four equal groups in triplicates. Group 1 received 400 mg/kg b.w. Echinacea in intra peritoneal injection. Group 2 received 0.5% Echinacea in their daily food. Group 3 and 4 were considered as injection control and oral control, respectively. Fish were bled on day 0, 10, 20, 30 and 40 of study. Sera samples were assayed for immunological parameters: lysozyme activity, serum bactericidal activity, complement activity and NBT reduction assay. Blood samples were also used for hematological parameters: (PCV, Hb, RBC, WBC and Leukocyte differentiated count).
Results showed that serum lysozyme and bactericidal activity as well as complement and NBT reduction activity were significantly higher in i.p. treatment than the control group (p0.05) but WBC count and rate of heterophils showed an increase in injection treatment group compared with the control (p This study indicates that administration of E. purperea stimulates some nonspecific immune responses in grass carp and therefore it can be recommended as an herbal immunostimulant in fish.