The invention concerns a process for the preparation of a matrix for animal feed comprising the following steps: a) mixing granules of a raw material of plant or mineral origin, wherein each granule comprises one or more food additives adhered thereon in a certain amount; b) spraying the mixture of granules with a water-soluble coating mixture comprising a filming substance selected from starch and its derivatives, cellulose and its derivatives; c) obtaining the matrix for feed comprising fully or partially coated granules. Preferably, said food additive adhering to the granules of raw materials is a manganese salt, wherein said plant or mineral raw material is selected from the group consisting of calcium carbonate, hazelnut flour, corncob, semolina, sepiolite, bentonite, sugars and grape skins.