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April 21, 1975

Antibiotics in Meat Production

JAMA. 1975;232(3):292-293. doi:10.1001/jama.1975.03250030046022

THE USE of antibiotics in feeding animals is connected in a remarkable way to clinical medicine, for this use came as a by-product of the discovery of a new antibiotic, aureomycin (now known as chlortetracycline), in 1948. Aureomycin was the first of the tetracyclines, and it was immediately put to use for its "broad-spectrum" effectiveness against many pathogenic microorganisms. The fermentation that made aureomycin also produced vitamin B12, which is needed for growing chickens and pigs on feeds based on vegetable proteins, such as soybean meal, feeds deficient in vitamin B12. The crude fermentation residues contained, in addition to vitamin B12, small amounts of aureomycin that made the animals grow more rapidly than when fed a "complete" diet.1 A few grams of antibiotics such as a tetracycline, penicillin, or streptomycin in a ton of feed will increase growth, apparently because farm animals normally harbor susceptible intestinal