Screening of selected feedstuffs by juvenile pacu, Piaractus brachypomus (Cuvier, 1818)

Apparent crude protein (ADC(CP)), crude fat (ADC(CF)), gross energy (ADC(GE)) and phosphorus (ADC(P)) digestibility coefficients of several typical and novel feedstuffs were determined to be utilized in formulated diets of pacu (20.3 +/- 5.6 g). The tested feedstuffs included two fish meals, four terrestrial animal by-products, three plant protein concentrates, six high-protein plant meals and two low-protein plant meals. The values of ADC(CP) varied in different fish meals ranging from 96.17% for Koli fish meal to 95.17% for Sardine fish meal. The values of ADC(CP) for plant protein concentrates ranged from 92.17% for wheat gluten meal to 93.17% for corn gluten meal. The values of ADC(CP) ranged from 50.17% for faba bean meal to 73.43% for spirulina meal. The ADC(P) ranged from 51.77% for low-protein plant meals to 85.72% for fish meals. A significant (p < 0.05) linear regression (r(2) = 0.96) was observed among in vivo ADC(CP) of five feedstuff classes fed to pacu and in vitro ADC(CP). Based on these observations, we conclude that pacu as an omnivorous fish tend to utilize nutrient-rich ingredients from high-protein plant meals to fish meals.