Vegetable oils are an important part of human diet. By-products from vegetable oil’s industry are a reliable source of protein and fat, with variable amounts of fibre, and a source of phenolic compounds. However, their digestibility by some animals is difficult due to polysaccharides and lignin content. This work aims to assess the use of sunflower cake (SFC), rapeseed cake (RSC) and soybean cake (SBC) as substrate in solid-state fermentation (SSF) with filamentous fungi Rhyzopus oryzae and Aspergillus ibericus, for the production of animal feed additives and bioactive substances such as lignocellulolytic enzymes and antioxidant phenolic compounds. Results showed the highest cellulase and xylanase activities were achieved with A. ibericus using SFC and SBC as substrates. Highest β-glucosidase activity was observed in SSF with R. oryzae using RSC as substrate. R. oryzae release the maximum amount of total phenols and SSF improved antioxidant capacity of RSC and SBC extracts.