Brown seaweed (“Ascophyllum nodosum”) to Nile tilapia fingerlings

Abstract

Two trials were conducted to determine the apparent digestibility of dry matter, crude protein and gross energy from brown seaweed Ascophyllum nodosum and it level of inclusion in wet diets for Nile tilapia fingerlings. Forty fishes with average body weight of 74.75± 4.0g, were used in the digestibility experiment. For digestibility coefficients determination, faeces were collected in reproduction conical tanks (200L) adapted to this purpose. The apparent digestibility coefficients for dry matter, crude protein and gross energy were 58.13%, 43.48% and 23.92%. Forty five fishes with an initial average weight of 0.8±0.2g, were used in the study of A. nodosum inclusion and distributed in a completely randomized design with three treatments (0.0; 1.0 and 3.0%) and five replicates. No differences (P>0.05) on survival, carcass without viscera and the final body length were observed. The basal diet showed better values of performance parameters (final mean weight, mean weight gain, final biomass average, torso weight and heads weight) for 3.0% level and both were similar to the 1% level of A. nodosum. The Ascophyllum nodosum shown low apparent digestibility values and it isn’t recommended inclusion levels over 1% in wet feeds to Nile tilapia fingerlings.