The functional sample is a complete mixed feed for chickens containing 80 g/kg of non-extruded linseed together with the enzyme xylanase at a dose of 0.1 g/kg. Feeding this new mixed feed for fattening chickens leads not only to improved performance and bone quality, which indicates an increase in the living conditions of the breed, but also to the enrichment of the breast muscle with anti-inflammatory n-3 fatty acids. The ratio of n-6 to n-3 fatty acids in such meat is at the level recommended by the World Health Organization. The higher productivity and higher price of such enriched meat will ensure the efficiency of the production of mixed feed and meat.