Is there a difference in meat safety from swine raised with or without antibiotics?

To find out, three research scientists are investigating the occurrence of three common disease organisms in pigs from farm to slaughter. Their goal is to discover whether different production methods or handling techniques yield different amounts or kinds of foodborne bacterial organisms.

The research will give consumers information about whether pork produced under different labels, such as organic or antibiotic-free, yields any differences in food safety risks. It also will provide useful evidence to producers on which is safer, antibiotic or antibiotic-free production. 

To answer this uncertainty, project director Wondwossen Gebreyes, DVM, at North Carolina State University, along with Peter Bahnson, DVM, at the University of Wisconsin-Madison, Julie Funk, DVM, at The Ohio State University, and Morgan Morrow, DVM, North Carolina State University, are working together to compare pigs that receive antibiotics on farms with those that remain antibiotic free.

“We know that several foodborne pathogens are common in conventionally reared pigs,” says Bahnson, “But we still don’t have the solid science to understand the comparable risks involved in antibiotic free production.”

“In the context of this project, by conventionally reared we mean pigs that were exposed to therapeutic and non-therapeutic levels of antibiotics,” adds Gebreyes.

During the research project, Bahnson will focus on the presence of Salmonella bacteria in pork, while Gebreyes will examine for levels of Campylobacter bacteria and Funk will concentrate on Yersinia bacteria. Gebreyes will then conduct DNA fingerprint tests to assess the similarities or differences of all the three bacteria isolated from different production systems and geographical locations. Morrow is responsible for disseminating the research findings to producers and consumers. The USDA’s Cooperative State Research, Education and Extension Services has provided over $500,000 in funding for the study via its National Integrated Food Safety program.

The project will survey 60 different farms in three regions of the United States. Half of these farms include antibiotics in the feed of growing pigs, while the other half remain antibiotic free.

The scientists will follow through by taking samples at several points in the slaughter process to determine the relative importance of major slaughter activities in reducing contamination.  This will reveal which slaughter practices are most effective at preventing the transmission of antibiotic resistant bacteria from the live pigs to the carcass.

“This project is not meant to advocate for or against antibiotic use, but to provide the best possible information from pigs produced using both systems,” stresses Bahnson.

University of Wisconsin-Madison School of Veterinary Medicine