Effect of dietary Andrographis paniculata leaf extract on growth, immunity, and disease resistance against Aeromonas hydrophila in Pangasianodon hypopthalmus

ABSTRACT Aeromonas hydrophila severely hampers the farmed catfish production. A 60-day feeding trial was conducted to study the effect of Andrographis paniculata leaf extract on growth, immunomodulation, and disease outbreak against A. hydrophila in Pangasianodon hypophthalmus. A total of 180 juveniles of P. hypophthalmus (avg. wt. 123.33 ± 1.8 g) were distributed randomly in four groups following a completely randomized design in triplicate. Four experimental diets—C (no extract), T1 (1%), T2 (2%), and T3 (4%)—were prepared and fed twice daily. Growth metrics were calculated after 45 days and challenged with A. hydrophila. Relative percentage survival (RPS) was recorded over 15 days postchallenge. Results indicated that A. paniculata extract has a positive effect on hematobiochemical parameters and immune response. The highest (P < 0.05) pre- and postchallenge serum lysozyme activity, respiratory burst activity, and globulin level were found in the T2 group and lowest in the T0 group. Significantly (P < 0.05) higher percentage weight gain and SGR and lowest FCR were found in the T2 group than in the other groups. RPS was highest (P < 0.05) in the T2 group, followed by the T1 and T3 groups, compared to the control. Results suggest that A. paniculata leaf extract at a level of 2% could improve growth, immunity, and disease resistance against A. hydrophila by enhancing innate immunity in P. hypophthalmus.