To improve quality of meat by increasing the concentration of glycogen in meat, increasing the amount of oxidated type myoglobin and improving a meat color (B. C. S) by preventing oxidation of meat and enforcing muscular cells.

An additive for a feed for cattle is prepared by mixing three ingredients, a fixed amount of a glycose-containing material, a fixed amount of an ascorbic acid-containing material and inorganic ions, in a certain ratio. The aforesaid additive for the feed for cattle is fed in a fixed amount (in the Example, 40 g/day/cattle is fed by adding in a fattening feed) from 2 weeks before slaughtering to increase the amount of oxidized myoglobin after the slaughter and improve meat quality by improving meat color (B. C. S), texture and firmness owing to the prevention of oxidation and the enhancement of muscular cells.