This study assessed the effect of different feeding levels on the growth performance of Nile tilapia ( Oreochromis niloticus ) as well as on the stability of the biofloc system over a 9‐week experimental period. Three feeding levels were tested: BFT100 (100% of a complete ration), BFT75 (75% of a complete ration), and BFT50 (50% of a complete ration). A flow‐through system group (control) was feed 100% ration, while biofloc groups received 100% (BFT100), 75% (BFT75), or 50% (BFT50) of that ration. Each treatment was replicated 3 times, and the fish were reared in subsquare tanks (130 L) at a stocking density of 6.2 kg.m −3 per experimental unit (70 fish per tank). Growth performance was recorded at 14‐day intervals. All fish were counted and weighed to determine the total biomass. A sample of 30 fish per unit was measured and weighed individually to assess variability. Growth performance was significantly affected by feeding level ( p 0.05) to that of the control (0.75). In contrast, higher FCR values were recorded in BFT100 (1.09) and BFT50 (1.13), indicating reduced feeding efficiency under full feeding and excessive feed restriction, respectively. Notably, the BFT100 treatment was characterized by signs of organic overload under full‐feeding conditions, including floc disruption, increased nitrogenous waste levels, microbial imbalance, and mortalities. Accordingly, this study concludes that the biofloc system can withstand a 25% feed reduction without adverse effects on FCR when environmental stability is maintained. Resource optimization and progressive system management are likely the most effective approaches to enhance the sustainability of biofloc technology (BFT)–based tilapia rearing.
Langa et al. (Thu,) studied this question.