Raw and extruded flax seeds were blended with corn. feed mixts. (2-6%) and studied for primary nutrients, amino and fatty acids, antinutritional substances and total antioxidant potential. With the increase of the raw seeds shares in feed mixts., a significant increase in the content of antinutritional substances (up to approx. 900%) was obsd. Total antioxidant potential of feed mixts. containing up to 4% of the raw flax seeds was approx. const. Replacement of raw seeds by extruded grains in feed mixts. resulted in a decrease in the content of antinutritional substances (approx. twice), unsatd. fatty acids (by approx. 10%) and total antioxidant potential (by approx. 30-40%).