This study evaluated the effects of partial replacement of fish meal and meat and bone meal by plant based meal from the biofuel production chain on growth, digestive enzymes and biochemical parameters in silver catfish, Rhamdia quelen. This agro-byproduct was included in the silver catfish feed as an in natura byproduct or in the reduced antinutrients form, obtained after applying chemical treatment to meal. The inclusion of these ingredients was compared to the control treatment (protein based in animal meal) during nine weeks. Growth similar to the control was observed in fish fed with in nature or treated chemically crambe meal in the diet. Inclusion of in natura crambe meal reduced acid protease activity and plasma cholesterol, but did not alter hepatic biochemical parameters. Lower glycogen and glucose concentration in the liver and increase in aspartate aminotransferase were found in fish fed treated crambe meal, signaling an energy deficiency condition. The similar growth response coupled to slight metabolic and digestive changes with in nature crambe meal in relation to the treated meal may indicate that in the inclusion level used this ingredient does not require prior reduction of antinutrients.
vegetable protein; animal meal; Rhamdia quelen; growth; metabolism
