Growth Performance, Product Quality and Cost-Effectiveness of Alternative Protein Sources Replacing Fishmeal in Penaeus vannamei Reared in Biofloc Systems: Medium- and Large-Scale Studies

Fishmeal (FM) reduction can improve shrimp feed sustainability, but low FM formulations remain insufficiently validated across production stages, scales, and post-harvest quality traits. This study evaluated alternative protein strategies for Penaeus vannamei reared under super-intensive biofloc technology (BFT) at different production scales. In a medium-scale grow-out trial, a Control diet containing 15% FM was compared with diets containing 7.5% FM using animal-derived proteins (A7.5) or combined animal- and plant-derived proteins (AP7.5). AP7.5 maintained growth and apparent feed conversion comparable to those of the Control diet, whereas A7.5 showed poorer performance. Post-harvest quality was assessed in commercial-size shrimp during refrigerated storage without antimelanosis treatment. Sensory differences were limited shortly after harvest but became more evident during storage, with AP7.5 maintaining a comparatively stable sensory profile and showing lower panel-assessed melanosis after seven days. Subsequently, the AP7.5 diet was validated against the Control in a pilot large-scale trial covering the juvenile and grow-out phases, maintaining comparable growth, economic conversion ratio, and profitability index. Sensitivity analysis further showed that its relative economic performance was maintained across simulated FM and shrimp price scenarios and became more favorable as FM prices increased. In conclusion, the consistent productive and economic performance of AP7.5 across production stages and scales, together with maintained sensory quality and lower panel-assessed melanosis, supports its potential as a scalable low-FM strategy for BFT shrimp production.