Growth-promoting Activity for Pigs of Inactivated Penicillin

Abstract

IT has been shown by many workers that the regular administration of very small doses of most antibiotics, including penicillin, will significantly increase the rate of growth of many species of animals. Extensive investigation, however, has not clearly demonstrated the mechanism or mechanisms by which such a benefit is derived, although it is generally considered that the mode or modes of action are entirely dependent upon the antibacterial activity of the antibiotic employed¹. It has been suggested, however, that autoclaved penicillin when given by daily injection, but not by mouth, will increase the growth-rate of chicks².