Abstract
The nursery phase in autumn is an important strategy for scaling up tilapia farming in subtropical regions, which otherwise suffers from a lack of fingerlings in winter. Tilapia nursery is carried out in a semi-intensive system in ponds; however, the biofloc technology system (BFT) has productive, environmental and health advantages. This study aimed to compare the production of Nile tilapia (Oreochromis niloticus) juveniles in two rearing systems during autumn through the evaluation of zootechnical, environmental, and hematological parameters, as well as production costs. In each system, four experimental units were used on a pilot scale and stocked with fingerlings with an average weight of 1.95 ± 0.32g. In the semi-intensive system, 25 m³ ponds were used, and each was stocked with 1,100 fingerlings (44 fish.m− 3). In the super-intensive system, 4 m³ circular tanks were used, each stocked with 2,200 fingerlings (550 fish.m− 3). The production of tilapia juveniles in BFT showed greater stability of water quality parameters throughout rearing in association with higher water temperature owing to the greenhouse. This allowed similar growth between fish in both systems, but with productivity 12.7x higher in BFT, while consuming 29.6x less water. Hematological parameters among fish in the two systems were also similar. Finally, BFT showed a lower total operating cost.