To obtain a mixed formula feed having the same cost as that of a first-class formula feed, an increased growth rate and a reduced feed consumption, by the addition and mixing of a developed additive having a nutrition balance.

This mixed formula feed is obtained by blending a well-known formula feed with 0.5-1% of a nutrition balance agent prepared by previously fermenting soybean curd refuse as a waste of tofu processing with Bacillus subtilis of a cellulase, etc., to give a hydrolyzate, dehydrating and drying the hydrolyzate, adding lipase and reductase enzyme powder for promoting digestion after intake in the body to the hydrolyzate, further adding spiral fresh water algae and marine algae of green laver having hemopoietic role, dried vegetable powder, tea power, brewer's grain powder, adlay powder, Zizania latifolia powder, etc. Consequently, the mortality rate in pig raising is dropped from 30% to zero, mortality rate in poultry farming is dropped from 7% to ≤1% and mortality rate in fry for dried young sardines for raising eels is dropped from 50-70% to ≤2%.