Enhancement of immune response in catla catla(Ham.) by ethanolic extract of cynodon dactylon (L.) pers. mixed diet

Abstract

Traditionally used grass Cynodon dactylon (L.) was used to study the antibacterial effect of aqueous and ethanolic extract were investigated against the gram positive bacteria and gram negative bacteria using disc diffusion, well in agar and microdilution methods. Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Aeromonas hydrophila were more susceptible in the ethanolic extract and no result was found in aqueous extract. After this study, the ethanolic extract was subjected to preliminary phytochemical screening, which proved that phenols, quinines and tannin were present in ethanolic extract of C. dactylon. Then, the ethanolic extract was analysed by Gas Chromatography and Mass Spectrophometry (GC-MS) which showed ten phytochemical components in the extract. After this finding, different concentrations like 0.05%, 0.5% and 5% of ethanolic extract was mixed with laboratory prepared fish diet as a feed supplement for further studies. Before the study of immune response in Catla catla, feed conversion ratio was performed for the preference of experimental fish feed, which confirmed that the fish preferred mostly the experimental diet than the normal diet. Followed by, the anaesthetic effect of clove oil was examined in the Catla catla.