PURPOSE: To accelerate growth of animal by adding yeast to sugar solution or theriac, fermenting and adding resultant material to feed.

CONSTITUTION: Concentration of a sugar is adjusted at about 5-25% and an yeast is added. Every kinds of yeasts are usable. Ferrous sulfate preventing poverty of blood, etc., are contained in the cultured extract by fermentation. Further, amino acid, vitamin, etc., are contained in a large amount. Said cultured extract is passed through a filter, etc., and removed yeast, then used. Adding amount of the resultant composition is preferably 0.5-5-wt.% as powder.