The Food and Drug Administration believes antibiotics should be used on livestock only to cure or prevent disease and not to promote growth, a high-ranking FDA official said July 13.

Principal deputy FDA commissioner Joshua Sharfstein said restrictions on livestock use would reduce the opportunity for bacteria to develop resistance to drugs used by humans.

Critics of the heavy antibotic use in livestock estimate 70 per cent of all antibiotics sold in the U.S. are used on food animals to promote weight gain.

Other groups say livestock’s share of antibiotic use is much lower and the bulk of it goes to fighting or preventing disease.

“Purposes other than for the advancement of animal or human health should not be considered judicious use,” and not allowed, Sharfstein said in a statement for a House hearing. “Eliminating these uses will not compromise the safety of food.”

Last fall, the American Veterinary Medical Association said Denmark’s voluntary ban on use of antibiotics for growth promotion “has not resulted in a significant reduction of antibiotic resistance in humans,” while disease and death in hogs increased.