Dietary protein requirement for armoured catfish juveniles (Hypostomus commersoni - Loricariidae)

Abstract

The objective of this study was to determine crude protein requirement for Hypostomus commersoni fingerlings. Seventy two fingerlings of armoured catfish were used with average weight of 2.44 ± 0.14g, distributed in nine tanks, totalizing eight fish per experimental unit. In a completely randomized design, with three treatments and three replications. Three experimental diets were prepared with protein levels of 25, 30 and 40% and isocaloric (3.500 kcal. kg-1). The fish were fed daily with at the rate of 5% of body weight for 10 weeks. Evaluated variables were final average weight, weight gain, specific growth rate (SGR), survival and body composition. Dietary levels of protein did not affect weight gain, specific growth rate and survival. Crude protein higher levels in the diet increased the deposition of protein and reduced body fat (p≤0.05). Levels of 25% crude protein in the diet of armored catfish are suffi cient for good growth performance, however, raise levels may be beneficial, increasing protein deposition in the carcass and reducing body fat.