Feed additive compositions for ruminants containing (A) at least one member selected from the group consisting of hydrogenated vegetable oil and hydrogenated animal oil each having a melting point of higher than 50° C. and lower than 90° C.; (B) not less than 0.05 wt % and not more than 6 wt % of lecithin; (C) not less than 30 wt % and less than 65 wt % of a biologically active substance; (D) not less than 0.01 wt % and less than 0.8 wt % of a natural vegetable oil; and not less than 0.1 wt % and less than 6 wt % of water exhibit high protection in the rumen and are also superior in dissolution in the lower gastrointestinal tract.