Digestible energy, protein, and energy–protein ratio requirements of Pseudoplatystoma reticulatum

Abstract

AbstractThe use of novel aquaculture species depends on the determination of their nutritional requirements. This study aims at determining dietary protein, energy, and protein–energy ratio requirements of juvenile striped surubim, Pseudoplatystoma reticulatum, an economically important carnivorous South American catfish for capture fisheries and highly regarded for fish farming purposes. Juvenile striped surubim (53.6 ± 1.30 g, n = 525) were randomly stocked (n = 7) in 75 test cages (210 L) and hand fed for 60 days, two daily meals, with 25 diets formulated to contain five levels of digestible protein (DP) (320, 360, 400, 440, and 480 g/kg) and five levels of digestible energy (DE) (15.1, 15.6, 16.1, 16.6, and 17.2 MJ/kg) in a completely randomized design, 5 × 5 factorial scheme (n = 3). Dietary energy and protein level affected performance, feed efficiency, and metabolism while the whole‐body composition was not affected by diets. Estimated dietary requirements for the best performance and best nutrient retention were 15.1 MJ/kg DE and 390 g/kg DP, therefore a 25.9 g/MJ of DP:DE ratio.