The culture of Nile tilapia (Oreochromis niloticus) juvenile at different culture technologies: autotrophic, bioflocs and synbiotic

Abstract

Nile tilapia is a widely produced species due to its rusticity and technological culture package. However, there is a knowledge gap in youth production using new technologies. Therefore, this work aimed to evaluate the production of juvenile Oreochromis niloticus in different culture technologies: autotrophic, synbiotic, and bioflocs, through of water quality parameters, plankton groups, bacterial counts and zootechnical performance. The experiment lasted 40 days, time needed to reach a commercial weight of juveniles, and used tilápia fry weighing 3.60 ± 0.32 g stocking density of 500 fish m−3 and fed with commercial feed (46% crude protein and 9% lipids). Before stocking the fish, the experimental units were prepared for 30 days with inorganic (potassium nitrate and superphosphate - autotrophic - AUT) and organic (sugar - bioflocs - BFT; rice bran fermented with probiotic - synbiotic - SYNB) addition and control group (CTL). Regarding water quality parameters, temperature, salinity, dissolved oxygen (DO) and pH were within those recommended for the culture of the species. The nitrogen compounds (TAN and N-NO2) and water footprint were lower in BFT and SYNB as compared than AUT and CTL. The phytoplankton community had significantly higher Bacillariophyta count in BFT and SYNB as compared than AUT and CLT, however Chlorophyta in AUT and Cyanophyta in BFT, SYNB and CTL, prevailed. Zooplankton showed dominance of Rotifera in all treatments, with higher values in SYNB and BFT (p < 0.05). BFT had the higher standard bacterial count, SYNB had the higher Bacillus sp. count, and AUT and CTL showed the lower microbial counts (p < 0.05). The zootechnical performance: final weight, yield, SGR, FCR, feed efficiency and Fulton condition factor were better (p < 0.05) in the BFT and SYNB treatments as compared than to the AUT and CTL. The FI (feed intake) did not show statistical differences between treatments (p > 0.05). Regarding survival, the lower (p < 0.05) was observed in the control treatment. Therefore, we can conclude that the BFT and SYNB systems are promising for improving the results of nitrogen compounds (TAN and N-NO2) control, water footprint, plankton community, bacterial and zootechnical production of juvenile Nile tilapia.