WASHINGTON, D.C. - Proposals to ban the use of antibiotics as a livestock growth promotant could drive up farmers costs without improving public health, skeptical lawmakers said Wednesday.

Legislation to ban the decades-old practice is unlikely to pass this year, said sponsor Louise Slaughter, but her plan is to move further next year. The Food and Drug Administration recommended on June 28 that antibiotics be used only to prevent or treat livestock disease.

FDA made its recommendation in a first-round version of a "guidance" document, which states the FDA's current thinking. Guidance papers do not carry weight of law but generally are accepted by industry.

The proposals grew out of concerns about how to preserve the effectiveness of antibiotics. FDA is looking for ways to reduce over-use of the drugs.

"Before we go down a path that will have a devastating economic impact on our agriculture industry, we must assure science drives this debate," said Illinois Republican John Shimkus at a House Energy and Commerce subcommittee hearing on Slaughter's bill.

Democrats and Republicans on the subcommittee expressed concerns about the science behind the ban, but Democrats said evidence favored action.

Officials from FDA, the Centers for Disease Control and Prevention, and the Agriculture Department said use of antibiotics by the livestock industry is a health concern.

"Using medically important antimicrobial drugs for production purposes is not in the interest of protecting and promoting the public health," said Deputy FDA Commissioner Joshua Sharfstein.

No conclusive evidence has been accepted as proving the direct link between human and animal drug resistance, especially because no specific testing has taken place in the United States, Shimkus said as he pressed on the officials on the panel. The CDC and FDA administrators said studies conducted in the United States and Denmark, which has a ban, show enough linkage.

Although Danish Veterinary and Food Administrator Per Henriksen said the Danish experience yielded good results, Randall Singer, associate professor of epidemiology at the University of Minnesota College of Veterinary Medicine, pointed out that livestock health suffered in Denmark after the ban.

"Animal diseases that had been kept under control now appeared as epidemics, as stated by the Danish themselves," said Singer.

Major U.S. livestock groups oppose the bill, citing high potential costs and possible shortage of veterinarians to oversee drug use in livestock.

(Reporting by Alina Selyukh, editing by Bernard Orr)

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