Comparative strategies for intensive shrimp production in ponds using biofloc technology system in Southern Brazil: Water quality, zootechnical performance and economic viability for Litopenaeus vannamei.

The present study aimed to compare a Litopenaeus vannamei culture throughout two short cycles and one long cycle of production in a BFT (biofloc technology) system. The study was conducted in six lined 600‐m2 ponds and was composed of two treatments with three replicates each: two short consecutive crops (SC) of 75 days and a 150‐day long cycle (LC). Stocking density was 42 shrimp m−2 for all cycles, and initial weight was 1.20 g in SC1 and LC and 1.40 g in SC2. Economic analysis was also carried out to compare the results of treatments. In terms of water quality, sedimentable solids and turbidity were significantly higher in the LC treatment. All other water quality parameters presented no significative differences between treatments, and mean values were maintained within the recommended levels for shrimp culture. There was a significant difference in the final average weights between treatments, with the value of the long treatment being greater than twice the values of the short cycles. The productivity did not differ significantly between the sum of the SC and LC treatments. Production data were assessed using economic indicators. The treatment results show positive Gross and Net Margin; however, SC1 negatively influenced the SC result, mainly for ML and IL. The best result of the profitability index was the LC. The results of the present study and considering the strategies used, there was no influence on productivity, but on profitability in the cultivation of L. vannamei in lined ponds under subtropical conditions. [ABSTRACT FROM AUTHOR]