By Dr. Hans H. Stein

December, 2013

On December 11, the Food and Drug Administration (FDA) announced a plan to limit the use of certain antimicrobials in food animals. The drugs at issue are those considered medically important in humans, including tetracyclines, penicillins and macrolides. The FDA's plan asks drug makers to voluntarily change the labels on their medically important antimicrobials to remove growth promotion as an indication. By law, drugs administered in animal feed cannot be used in a way inconsistent with their labeling, so this would effectively prohibit usage of antimicrobials as growth promoters. The FDA has also asked drug companies to revoke the targeted antimicrobials' over-the-counter status, so that a veterinarian's prescription would be required to use these medications for the purpose of disease prevention or treatment.

Companies have 90 days to inform the FDA whether or not they intend to comply, and then the changes called for in the plan will be phased in over the next three years. Two of the largest pharmaceutical companies, Zoetis and Elanco, have already agreed to abide by the new guidelines.

It should be noted that a group of antimicrobials that are not considered important in humans is not included in the new FDA recommendations. This group includes the ioniphores, carbadox, and several other antimicrobials, and these drugs can still be used as growth promoters in diets fed to pigs.

Last year, we produced a brochure intended to help producers make the transition to raising pigs without antimicrobial growth promoters (AGPs). The brochure describes a number of strategies for promoting growth, reducing disease exposure, and increasing resistance to disease among weanling pigs. Some of these strategies include:

• Weaning practices: Segregated early weaning and all-in-all-out production reduce disease pressure.
• Environmental controls: Keeping facilities at the proper temperature and avoiding crowding reduce stress on pigs, while pest control reduces pathogen exposure.
• Feeding pelleted or liquid diets: Pelleted and liquid diets enhance energy and nutrient digestibility and improve performance.
• Restricted feeding: Feeding small amounts several times per day instead of giving ad libitum access to feed means that less undigested feed is fermented in the hindgut, which reduces the incidence of diarrhea.
• Feeding alternative cereal grains: Hindgut fermentation of specific fibers present in barley, naked oats, and oats may reduce pathogens and increase the concentration of favorable microbes.
• Feed additives: Acidifiers, functional proteins, probiotics, prebiotics, copper, zinc, and mannan oligosaccharides may improve pig health and growth performance.
• Low protein diets: Reducing the amount of undigested protein that reaches the hindgut reduces microbial fermentation and diarrhea.

Some of these strategies will increase diet costs and thus reduce profitability. But following these guidelines will allow producers to manage weanling pigs without the use of AGPs with no loss of performance.

The brochure, "Strategies for managing weanling pigs fed no antibiotic growth promoters," can be downloaded from our website at http://nutrition.ansci.illinois.edu/SwineFocus003. Hard copies can also be requested from Illinois Extension offices.