R. Bras. Zootec.31/Mar/2025;54:e20240081.
Dietary protein levels for juvenile matrinxã (Brycon amazonicus) reared in biofloc and clear water systems
Rafaelle Borges Cunha
, Elizabeth Gusmão Affonso
, Sabrina Medeiros Suita
, Marcos Antônio da Silva
, Higo Andrade Abe
, Thiago Mendes de Freitas
ABSTRACT
This study evaluated the potential for rearing matrinxã (Brycon amazonicus) with different crude protein (CP) levels and using production performance, water quality, and animal welfare as indicators. To achieve this, 720 juvenile fish (3.65±0.17 g) were distributed in 24 experimental units (200 L). The study, which lasted for 60 days, followed a factorial design (2 × 4) with two production systems: biofloc technology (BFT) and clear water (CW) and four CP levels (24, 30, 36, and 42%) in the diet, with three repetitions for each. We found that the BFT system showed a lower total ammonia level (0.45±0.15 mg/L) compared with CW (1.16±0.50 mg/L). Fish produced in the BFT system exhibited better performance in terms of apparent feed conversion (1.06±0.15), productivity (7.68±2.38 g/m3), and survival (76.95±9.15%). The type of production system affected total leukocytes and neutrophils in the blood. Juvenile matrinxã can be fed a diet containing 30% CP in both production systems. Furthermore, the results demonstrated that bioflocs do not confer a direct benefit to juvenile matrinxã in terms of their feeding; however, the BFT system is a promising alternative for increasing the survival and improving animal welfare during the rearing phase.
Keywords: feeding; fish production; ideal protein; production system