The purpose of the present invention is to provide a method for manufacturing a feed additive composition for ruminants, said feed additive composition containing a biologically active substance showing a low solubility in water, having high protective properties in the rumen and having excellent elution properties in lower digestive tracts.The present invention pertains to a method for manufacturing a feed additive composition for ruminants having a particle diameter of 0.5-2 mm inclusive, said method comprising granulating, in water, a molten mixture which comprises (A) at least one member selected from a hardened vegetable oil and a hardened animal oil each having a melting point of 50-90oC exclusive, (B) lecithin and (C) a biologically active substance having a solubility of 0.001-60 g inclusive in 100 g of water at 20oC.
