Meat producers and buyers are slowly moving away from the routine use of antibiotics on farms and in feedlots, a welcome change that should be helped by the passage of federal legislation to require the phase out the use of most of these drugs.

Earlier this month, the country’s second largest food service company, Compass USA, announced it would require its suppliers to stop the use of antibiotics, other than for medical reasons, in chicken and pork. It is the first time a major food company has restricted pork purchases to reduce antibiotic use. Several companies have taken similar steps with chicken purchases.

The Food and Drug Administration late last month began the process of withdrawing its approval of Cipro-like antibiotics in poultry because the drugs were making it more difficult to treat human food poisoning. It is the first time the agency has moved to withdraw an agricultural antibiotic from the market because of concerns about antibiotic resistance harming human health.

In 2002, 21 percent of humans with Campylobacter, a common cause of bacterial food poisoning, were resistant to Cipro, according to the Centers for Disease Control and Prevention. When Baytril, one of two Cipro-like antibiotics, was approved by the FDA for use in poultry in 1995, resistance in human’s was negligible. Still, Bayer Corp., the sole maker of Baytril, may appeal the FDA ruling, slowing down its withdrawal. Another company, Abbott Laboratories, quickly agreed to withdraw a similar drug from the market.

Rather than go through the lengthy process one drug at a time, the Preservation of Antibiotics for Medical Treatment Act, sponsored by Sen. Olympia Snowe, would alleviate the problem all at once. It would require the FDA to withdraw the approval of non-therapeutic use of eight classes of antibiotics within two years. It would also require the manufacturers of animal drugs and medicated feed to make their records available to the CDC so it will be better able to track usage and resistance trends. The bill also authorizes the secretary of agriculture to make payments to defray the costs of farms transitioning away from the medicines with a priority given to small and family farms.

The Union of Concerned Scientists estimates that only 10 percent of the 22 million pounds of antibiotics used annually on livestock is for medical treatment. The rest is used to promote growth and to combat the effects of cramped, dirty conditions at some farms. The group estimates that the nontherapeutic use of drugs in livestock has increased 50 percent since 1985.

The routine use of antibiotics in livestock is unnecessary and potentially harmful to the animals and the humans who work with and eat them. The practice is slowly being phased out by market demand and government action. Federal legislation would accomplish this even more quickly.