Dietary guarana (Paullinia cupana) powder for tambaqui (Colossoma macropomum): growth, hemato-immunological parameters and bacterial challenge

Abstract The present study evaluated the effects of commercial guarana (Paullinia cupana) powder as a growth-promoter and natural antioxidant supplement in aquafeeds. In Experiment 1, fish were fed with graded levels of guarana powder (0, 1.25, 2.5, 5 and 10 g/kg) during 60 days. Growth, hemato-immunological and biochemical performance were evaluated in healthy fish and in fish after infection by Aeromonas jandaei. In Experiment 2, the supplemented feed was stored for 90 days, in which tests were carried out regarding the quantity of phenolic compounds and the inhibition of lipid peroxidation. As a result of Experiment 1, fish fed guarana-supplemented diets and infected by A. jandaei presented better parameters of leukocyte respiratory activity, total proteins, globulin, albumin, alanine aminotransferase (ALT), leukocytes, lymphocytes, neutrophils, monocytes and thrombocytes. As a result of Experiment 2, levels of phenolic compounds were not altered (p > 0.05) by the guarana-supplemented diets. An increase in the concentration of malondialdehyde (MDA) and a lower oxygen radical absorbance capacity (ORAC) was observed in the fish fed diets with the highest level of guarana supplementation. As conclusion, guarana did not impair productivity and revealed a possible cytoprotective and hepatoprotective effect in fish infected by A. jandaei. Therefore, guarana seems to be an interesting additive to be included at levels of up to 1% in special feeds to be used prior to stressful situations in aquaculture. Additionally, guarana had no protective effect against lipid peroxidation and showed a pro-oxidant effect in diets with higher supplementation levels.