PURPOSE: To prepare fermented feed containing high-quality proteins, in a short time, by fermenting animal excretions to produce proteins, mixing the fermented excretions with other proteinaceout materials, and again fermenting the mixture.

CONSTITUTION: Animal excretions such as fowl droppings, are mixed with vegetable powders such as sawdust, wood shavings, bark, chip dust, etc., and fermentation bacteria, and fermented to obtain a mixture of the animal excretions and proteins. The mixture is mixed with one or more proteinaceous materials such as rice bran, soybean oil meal, fish meal, etc., and yeast, and is fermented to obtain the objective feed.