all rights reserved feedstuffs are composed of feed materials derived from products of vegetal, animal or mineral origin. they are used in their natural state or have been processed. In the case of feed materials of animal origin, the process of transforming animal by-products into valuable products [for example, meat and bone meal (MBM) and fat] is called "rendering". In ec regulation 1774/2002, 1 these products are called processed animal proteins (paps), but only pap material from category 3, which consists of animal by-products that are fit for human consumption, can be used to feed farm animals. under this definition, paps do not include blood products, milk or milkbased products, colostrum, gelatine, hydrolysed proteins and dicalcium phosphate. of all the materials listed in category 1 or category 2, MBM is one of the most important paps among the processed animal by-products derived from the processing because of its quantity and market value. MBM is defined in commission directive 98/67/ec as "the product obtained by heating, drying and grinding whole or parts of warm-blooded land animals from which the fat might have been partially extracted or physically removed". the product should be substantially free of hooves, horn, bristle, hair and feathers, as well as digestive tract content. 2 for more than 10 years, MBM has been the focal point of the control laboratories and management bodies responsible for addressing the bovine