Silage production from olive mil wastes

Within the European Union, approximately 129 Mtons of food waste were generated in 2011, and about 52% of them derived from post-processing activities. The most common by-products originated from the food industry are spent coffee grounds, sugar cane waste, and fruit peels, while the main agricultural wastes are livestock slurry, manure, crop residue, and woodland pruning and maintenance wastes. The olive tree is cultivated worldwide, and more than 90% of the cultivated area is located in the Mediterranean basin. The olive oil extraction is carried out using two- or three-phase centrifuge systems. The olive mill wastes can be incorporated into the diets of productive animals, especially ruminants, due to their high fiber content. The aim of this work was to investigate the optimum conditions for silage production for animal food using olive oil wastes from a diphasic olive mill facility. Olive mill waste and straw were the base materials for silage composition: 53 to 55% and 45 to 47%, respectively (dry weight basis). Different mass ratios of molasse (0 to 4%) and urea (0 to 1%) per olive mill mass (dry weight) were used. The presence of urea and the absence of molasses turned out to be inhibitory factors for the silage process. The highest molasses rates the highest efficiency of silage production.