Leaf powder of Eupatorium odoratum Enhances non-specific immune response and resistance to Aeromonas hydrophila Infection in Cyprinus carpio (Linn. 1758)

Aeromonas hydrophila is considered a major bacterial pathogen in Indian aquaculture. The various experimental trials are being conducted as a control measure against A. hydrophila infection in fish. The study evaluated the effect of dietary inclusion of crude dried leaf powder of Eupatorium odoratum at 0.5, 1.0 and 1.5% to study the immune response and disease resistance in fingerlings of Cyprinus carpio experimentally infected with A. hydrophila.

The fingerlings of C. carpio were orally administered crude dried leaf powder of E. odoratum at 0.5, 1.0 and 1.5% through feed for 55 days followed by challenge with A. hydrophila. The biochemical, haematological and immunological parameters of the fish samples analyzed on 55^th and 62^nd day of the feeding trial to evaluate the immune response and disease resistance.

The comparative analysis of biochemicals, haematological and immunological parameters confirmed that the fingerlings fed with dry crude leaf powder of E. odoratum at 0.5–1.0% showed enhanced leucocytes count, hemoglobin, lysozyme activity, superoxide anion production, bactericidal activity, the total protein and albumin content in pre and post-infected experimental groups. The highest relative survival percentage of fingerlings was recorded in groups fed with 1.0% dietary inclusion of dried crude leaf powder of E. odoratum. Thus, the study concludes that dietary inclusion of crude dried leaf powder of E. odoratum at 1.0% level imparts improved immune response and resistance against A. hydrophila infection.