One third of the world’s fishing produce is not directly used for human consumption. Instead, it is used for making animal food or
is wasted as residue. It would be ideal to use the raw material thoroughly and to recover by-products, preventing the generation of
residues. With the objectives of increasing the income and the production of the industry, as well as minimizing environmental and
health problems from fish residue, chemical silage from Tilapia (Oreochromis niloticus) processing residues was developed after
homogenization and acidification of the biomass with 3% formic acid: propionic, 1:1, addition of antioxidant BHT and maintenance of
pH at approximately 4.0. Analyses to determine the moisture, protein, lipids and ash were carried out. The amino acids were examined
in an auto analyzer after acid hydrolysis, except for the tryptophan which was determined through colorimetry. The tilapia silage
presented contents that were similar to or higher than the FAO standards for all essential amino acids, except for the tryptophan. The
highest values found were for glutamic acid, lysine and leucine. The results indicate a potential use of the silage prepared from the
Nile tilapia processing residue as a protein source in the manufacturing of fish food.
Keywords: amino acids, fish residue, by-products.