Oilcakes are coarse residue remained after extraction of oil seeds or oleaginous fruits. Rich in protein and minerals, they constitute the second class of the largest animal food after cereals. With their high tenor on cellulose, digestible only by ruminant animals, oilcakes are the main protein source making it highly desirable for animal feed. Oilcakes may be broken up and sold or be ground into oil meal. Oil cakes from certain seeds such as castor beans and tung nuts are toxic and are used as fertilizers rather than feed..