Feeds and foods for fishes comprising kasugamycin

Feeds and foods for fishes comprising kasugamycin.. J3A. Accelerating of the growth of animals and fishes is effected by adding a very small amount of kasugamycin to ordinary feeds for animals and foods for fishes. The feeds are obtained by admixing animal feeds or fish foods uniformly with at least a member selected from the group consisting of a culture broth after cultivation of a kasugamycin-producing strain of sTreptomyces, a culture filtrate, a treated substance such as concentrated culture broth, crude kasugamycin extracted therefrom and pure crystals of kasugamycin.