To provide a method for treating vegetable strained lees, by which the vegetable strained lees such as beer lees can be treated at a low cost to effectively recycled the resource, and to provide an inexpensive feed obtained by the treating method and having a high nutritive value.

This method for treating the vegetable strained lees is characterized by degrading at least a part of the vegetable strained lees produced as a by-product in a food-producing process with the larva of Drosophila melanogaster, and further degrading the product with the larva of Musca domestica to obtain the animal resource originated from the larva or chrysalises of Musca domestica and the digestion residues of the larvae. The feed is obtained by drying the animal resources and the digestion residues obtained by the above-descried method in a mixed state.