LAUSR

The study of alternative protein sources is very important to lower the cost of aquafeeds. In this study, the use of waste from the processing of silver catfish (Rhamdia quelen) in the diet of juveniles of this species was evaluated. This feed was used in a recirculation system with 16 polypropylene tanks (280 L), each one containing 50 fish (initial weight = 5.50 ± 0.09 g). Fish were tested on four diets (37% crude protein and 3200 kcal kg-1 digestible energy): a control diet composed of swine meat and bone meal, one with meal made from silver catfish carcasses with viscera, a diet of meal from carcasses without viscera, and a diet of fish meal made from the whole fish. The data measured were final weight, condition factor, specific growth rate, feed conversion ratio, daily weight gain, and protein retention rate of fishes on different diets. Overall higher final weight (50.5 g), specific growth rate (3.9% day-1), feed conversion (1.3:1), and deposition of body protein (6.3 g) was observed for fish fed with the diet containing carcass meal from silver catfish with viscera than on the other diets. The incorporation of waste meal from the processing of silver catfish into the diet is viable for achieving fish growth.