Zootechnical and economic indicators of the tilapia culture in net cages of different sizes

Abstract

The present study aimed to compare the main zootechnical and economic indicators of farming tilapia in super-intensive system, developed in two different net cages dimensions: 6 and 18 m³, using 12,960 juveniles male reversed Nile tilapia (Oreochromis niloticus), supreme strain, with an initial average weight of 32.0 g (± 0.85) for 6 m³ net cages and 88.5 g (± 0.96) for 18 m³ net cages. The fish were fed three times a day with commercial extruded ration, crude protein levels from 40 to 32%, particle size from 2 to 8 mm and daily feeding rate starting with 8% of live weight (LW), decreasing up to 1% LW. It was concluded that, although no statistical difference in most zootechnical indicators (P>0.05), the production of tilapias in bigger net cages resulted in lower average total cost and higher rentability per kg of fish produced, 34.4% higher, resulting in better profitability.