Antibiotic use in food-animal production gets a lot of attention, but accuracy doesn’t always follow. To better determine the amount of antibiotics actually used in pork production, a team of researchers, led by Mike Apley, a clinical pharmacologist and professor of clinical sciences at Kansas State University, investigated the topic.

The end result is a paper entitled “Use Estimates of In-Feed Antimicrobials in Swine Production in the United States," which was published in the March issue of the scientific journal Foodborne Pathogens and Disease. It shows that opponents of antibiotics use in food-animal production have greatly overestimated the application amounts.

The study found that about 1.6 million pounds of antibiotics are used in pork production annually for growth promotion/nutritional efficiency and disease prevention. A 2001 report, “Hogging It,” from the Union of Concerned Scientists claimed that use for those two purposes totaled 10.3 million pounds annually.

Add in antibiotics used for disease treatment, and the study revealed that 2.8 million pounds of antibiotics are used per year. That is 368 percent less than the amount that UCS points to regarding use just for growth promotion/nutritional efficiency and disease prevention.

To collect their data, the research team, which also involved the University of Minnesota, the American Association of Swine Veterinarians and USDA’s Animal and Plant Health Inspection Service, Veterinary Services, used data from a 2006 USDA’s Animal Health Monitoring System, or NAHMS, Swine 2006 Study, which is a newer version than opponents often cite. But the researchers also involved swine veterinarians to measure product usage on the farm, identify what it’s targeted to prevent and the dosage.

 "The model for the final calculations had been used before," Apley says. “However, in our estimate, we started at farm-level survey data of producers from the USDA study and then used an additional veterinary practitioner survey to more precisely define in-feed antibiotic periods of use and dosing regimens for 102 different combinations of antibiotics, production phases and reasons for use.”

In all, 27 swine-specific veterinarians participated, representing a broad range of producers and a total of 48.791 million market hogs, or about 81 percent of U.S. market hog at the time. 

The researchers also asked three companies that sell a swine-only, in-feed antibiotic to evaluate the study’s estimates and assess how accurately actual sales were represented. Two companies indicated the team’s assessment matched up well. The other responded that the estimate varied from actual sales by approximately 50 percent. However, of the three, this last one was a lesser-used antimicrobial.

“We felt that an external validation was necessary and were pleased to find that the team’s efforts had resulted in reasonable estimates," Apley adds.

As a producer, National Pork Producers Council President R.C. Hunt, from Wilson, N.C., responds, “Pork producers use antibiotics carefully and judiciously to protect public health and the health of their animals and to produce safe food. Pork producers do not overuse antibiotics. We work with veterinarians to carefully consider if antibiotics are necessary and which ones to use.

To denigrate America’s hog farmers by deliberately peddling misinformation about how they care for their animals is despicable,” he adds, in regard to UCS’ and other opponents’ allegations.

NPPC argues that the Kansas State-based study also belies opponents’ common claim that 80 percent of all antibiotics sold are used to promote growth in food-animals. NPPC emphasizes that the 80 percent figure always has been at best a guess because there is no reliable data on human uses of antibiotics.

Several groups and lawmakers have pushed a theory that antibiotics use in food animals is leading to treatment failures in people who develop antibiotic-resistant illnesses. They support legislation to ban the use in livestock of antibiotics that prevent or control diseases and of ones that improve nutritional efficiency. NPPC argues that “numerous peer-reviewed risk assessments have shown a ‘negligible’ risk to human health of antibiotics use in livestock production”

The paper classifies the results by use category -- growth promotion, disease prevention and disease therapy – as well as by the importance to human medicine as defined by the Food and Drug Administration. The team grouped the results in this manner to better inform the discussion on food animal antibiotic use.

“Gross tonnage estimates of overall use serve us little other than as sound bites,” Apley says. “While our estimates of use must still be used with great care, we can now at least start to properly frame discussions based on specific antibiotics and bacteria of interest."

To review “Use Estimates of In-Feed Antimicrobials in Swine Production in the United States," click here.

You can find more information about antibiotics use in pork production here.