Apparent digestibility of the energy and nutrients of agro-industrial by-products for Nile tilapia

Abstract

This study was carried out aimed to determine the dry matter, crude protein and gross energy apparent digestibility coefficients of agro-industrial by-products palm kernel cake, cotton seed meal, mesquite pods meal, aerial parts of cassava meal and cocoa meal for Nile tilapia (Oreochromis niloticus). One hundred and fifty sexually reverted fishes, with weight of 40 ± 2.6g were spread across to teen net pens of 60L, installed in five polyethylene boxes (310L) and six hatchers adapted for the digestibility trial (200L), in an entirely randomized layout with five treatments and three repetitions. The apparent digestibility coefficients determination was performed by the indirect method, using 0.10% chromic oxide (Cr2O3), as marker. Apparent digestibility coefficients of dry matter, crude protein and gross energy were, respectively, 56.63; 75.87 and 66.87 for palm kernel cake; 48.31; 80.51 and 39,63 for cotton seed meal; 48.69; 51.61 and 30.48 for mesquite pods meal; 50.22; 49.83 and 29.29 for aerial parts of cassava meal and; 43.87; 38.47 and 23.13 for cocoa meal.