Utilização de alga marinha (Kappa phycusalvarezii) na alimentação de tilápias-do-nilo (Oreochromis niloticus)

Abstract

To evaluate the influence of different levels of inclusion of Kappaphycusalvarezii meal on the diet formulation of 300 Nile tilapia juveniles (Oreochromisniloticus) with an average initial weight of 1.3583 g ± 0.0213, four treatments were proposed (T1 - 0%; T2 - 3%; T3 - 6%; T4 - 9% inclusion of K. alvarezii flour). The experiment was carried out in a recirculation aquaculture system, with 20 experimental units, installed in the Laboratório de Nutrição e Produção de EspéciesOrnamentais (LNPEO) of IFES. The pelleted feeds were processed in the same laboratory where the field part was developed. In addition to the tests with Nile tilapia juveniles development, the characteristics of the pelleted feeds were also analyzed: buoyancy, dissociation and density. There was no influence on the inclusion of K. alvarezii meal in the development parameters (P > 0.05) of Nile tilapia juveniles. It was observed that the treatment with 6 % inclusion of K. alvarezii meal promoted biomass (g) lower than the control treatment (P < 0.05). There was no effect of the inclusion of K. alvarezii meal on the survival of Nile tilapia juveniles. But the survival averages were lower than expected for crops of the species in a recirculating aquaculture system. There was no effect of the inclusion of K. alvarezii meal on the dissociation and buoyancy of the feed pellets, but there was no significant effect (P < 0.05) on feed density. The inclusion of 9% of K. alvarezii meal decreased the density of the feed. Further tests should be performed to evaluate the quality of the pellets with inclusion of K. alvarezii meal. Inclusion should be tested in other types of feed processing, such as extrusion.