Physiological response and performance of tambaqui fed with diets supplemented with Amazonian nut

The present study evaluated the effectiveness of Amazonian nut (Bertholletia excelsa) as an alternative source of vegetal protein in tambaqui (Colossoma macropomum) diet. Performance and physiological status of fish fed for 60 days were evaluated. Four experimental isonitrogenous diets with 36% crude protein were formulated with increasing levels of nut meal (0, 10, 20 and 30%). Results showed the same growth performance for fish fed with diet with different levels of Amazonian nut than that without this ingredient (control). Analysis of physiological parameters (hematocrit, erythrocyte number, hemoglobin concentration, hematimetric indexes, total plasma protein and plasma glucose) corroborate these results, with no significant differences among treatments. Therefore, adding up to 30% of Amazonian nut in tambaqui diet there is no negative effect on physiological homeostasis and growth performance, indicating that the Amazonian nut is a promising alternative dietary protein source ingredient for tambaqui.