The objective ofthis study was to determine the quality and composition of fatty acid in thelipid fraction of silages obtained from the residue of tilapia processing. Stratificationof the lipid layer of the silages occurred at different times among the twotypes of silage (acid and fermented) and the greatest volume of oil was observedin acid silage (8.67% p/p). Although acid silage was more oxidized, it showedlower contents of free fatty acids probably because the degree of hydrolysisof its components is lower than that of fermented silage. Fatty acid compositiondid not differ among processes inasmuch as level of ϖ-3was slightly higher in fermented silage. According to the degree of saturation,monounsaturated fatty acids stood out as the predominant category in acid andfermented silages with values of 39.69% and 33.39%, respectively. The use ofantioxidants in the silage is needed because the process of production is carriedout at temperatures higher than room temperature. The oil in the silages hasexcellent nutritional value and contains fatty acids essential for animal feeding.
