Manejo e nutrição de tilápias em sistema BFT

Abstract

Tilapia production is booming all over the world. However, environmental, sanitary and water problems have caused concerns for producers. In this scenario, alternative tilapia production for these problems has been sought, such as the use of the biofloc system (BFT). This technology has proven to be an excellent alternative, mainly for optimizing the production of larger and more disease-resistant juveniles, reducing the cultivation cycle. One of the major concerns with this system is the excessive amount of sedimentable solids, which despite being rich in nutrients, if not reused correctly, could be a source of environmental pollution. The general objective of this work was to evaluate metabolic responses of tilapia in different production systems and management in BFT system, in addition to evaluating the inclusion of biofloc flour in diets for this species. In all, 3 biological assays were conducted. In the first, the lipid profile, metabolic and oxidative parameters and the bromatological composition of tilapia fillet grown for 150 days in a biofloc system and soil tank were evaluated. In the second, the compensatory growth of tilapia reared at high densities in BFT and transferred to a recirculation system with low density for 60 days was evaluated. In the third work, the inclusion of biofloc flour (4, 8, 12 and 16%) in the tilapia diet for 49 days was evaluated. In the first experiment, fish reared in the BFT system showed improvement in fillet quality and fish metabolism, without changing the lipid profile. In the second and third experiments, BFT (both the system and the inclusion of flour) proved to be an excellent source of protection against oxidative stress, as tilapia showed significant metabolic responses. Tilapia reared at high density in an initial period of 30 days may show compensatory growth after this period. As for the inclusion of biofloc flour in the diet, it was observed that high inclusions can limit fish growth.