LAUSR

Abstract Herbal extracts have been proven to improve immunity, growth rate and appetite, as well as being antihepatotoxic they are important alternatives to synthetic antibiotics and chemotherapeutics. In this study, Papaveraceae extracts (PE), as alkaloids (quaternary benzophenanthridine and protopine) source were incorporated into the diet of striped catfish, Pangasianodon hypophthalmus, to assess their effects on growth, feed utilisation and digestibility, body composition, product quality and pathogen response. PE was supplemented at 0.7 g/kg (HLPE) and 0.35 g/kg (LLPE) in 30%–35% proteinous diet for 126 days, to determine the effects relative to control group (CC). Growth performance of P. hypophthalmus, measured by weight gain, was improved by 35 % and 25 % in LLPE and HLPE, respectively, compared to CC. The highest protein digestibility, thermal growth coefficient and feed conversion ratio was found in LLPE group. There were no significant differences to proximate composition and colouration of P. hypophthalmus fillets fed PE. After challenging with Aeromonas hydrophila, serum biochemical indices decreased significantly in HLPE treated group. To avoid deleterious effects on P. hypophthalmus fillets and nutritional quality, 0.35 g/kg PE can recommend as safe and economically viable dose for commercial pangasius farming, although curative action against A. hydrophila may require higher dose.