Erva-mate, Ilex paraguariensis A. St. Hil., como aditivo funcional em dieta para juvenis de jundiá, Rhamdia quelen

Abstract

In fish farming, nutrition not only modulates growth, but also has a direct influence on the health and body composition of fish. The use of nutraceutical ingredients in aquaculture diets can bring productive benefits. In this sense, the present study aimed to evaluate the effect of the inclusion of yerba mate, Ilex paraguariensis A. St. Hil., as a functional additive in the diet of jundiá juveniles, Rhamdia quelen. For this purpose, five isoproteic and isoenergetic diets were formulated to meet the nutritional requirements of jundiá and supplemented with increasing levels of yerba mate powder (0.0, 0.5, 1.0, and 2.0%), in a completely randomized design, in triplicate. The diets were prepared with certified organic ingredients and offered for 60 days to jundiá juveniles (41.59±0.32 g; 17.24±0.21 cm) stocked (8 fish/experimental unit) in 12 rectangular polyethylene tanks (55 L useful volume), connected to a heated (~28°C) and salinized (~3‰) water recirculation system, with individual aeration. At the end of the feeding period, survival, feed efficiency, growth performance, somatic indices, chemical composition, and total phenolic compound concentration in the fillet, as well as lipid oxidation of the fillet of jundiá juveniles over 90 days of frozen storage (-20°C), were evaluated. The inclusion of yerba mate in the diet positively influenced fish growth, with the best results for the 1% concentration. Dietary supplementation of yerba mate also showed an antioxidant effect on fillets, with significantly higher lipid oxidation in jundiá juveniles fed the control diet (without yerba mate). Survival, somatic indices, centesimal composition, and total phenolic compound concentration in the fillet, on the other hand, were not influenced by dietary treatments. The results indicate the potential use of I. paraguariensis as a functional additive in diets for R. quelen.