[Problem] To promote the early weight increase of livestock, reduce blood triglyceride levels and obtain good meat quality. [Solution] The invention offers a feed composition comprising 0.01-1 wt % of koji obtained by growing Aspergillus on a substrate containing a substance anaerobically fermented by a yeast. Additionally, it offers a livestock raising method comprising feeding the livestock a feed composition obtained by adding, to a common feed composition, koji in an amount of 0.01-1 wt % with respect to the total weight of the feed composition. In particular, the koji is obtained by growing Aspergillus on a substrate containing a substance anaerobically fermented by a yeast, the Aspergillus being chosen from the group consisting of Asp. oryzae, Asp. awamori and Asp. sojae.
