As of last month, the use of antibiotics on farms is forever changed. The U.S. Food and Drug Administration released its final version of Guidance 209, which will implement two significant changes in how antibiotics are used on the farm. 

Specifically, FDA is zeroing in on the subtherapeutic applications of antibiotics that are “medically important” to humans. That covers about half of the feed-grade antimicrobials used today, estimates Rich Carnevale, DVM, Animal Health Institute’s vice president of regulatory, scientific and international affairs.

First, Guidance 209 calls for a voluntary end to antibiotics use for growth promotion or nutritional efficiency purposes in food-animal production. Antibiotics use will be applied only to disease prevention, treatment and control as those are therapeutic uses and essential to protect animal health. Products that carry only prevention, control and treatment label claims will not be affected by FDA's new policy, but that rarely applies to in-feed products. There are some questions about water-based medications, as FDA hasn't spelled out the plans for those.

Second, there will be more veterinary oversight in the form of Veterinary Feed Directives. This means “a veterinarian will have to write an order to incorporate any medically important antimicrobial products into animal feed,” says Liz Wagstrom, chief veterinarian for the National Pork Producers Council. “We’ve always been supportive of veterinary oversight and judicious use of antibiotics. A veterinarian should always be involved in the decision-making process.”

As a result, many products will move from an over-the-counter option to more of a prescription-based system.  

Antibiotics Use is Overblown

Antibiotics 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 researchers revealed that 2.8 million pounds of antibiotics are used annually. That is 368 percent less than the amount that UCS points to regarding use just for growth promotion/nutritional efficiency and disease prevention.

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 USDA’s National Animal Health Monitoring System 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 the pathogen that it’s targeted to prevent and the dosage. The point was 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,” Apley says.

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 hogs 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 said the estimate varied from actual sales by about 50 percent. However, of the three, this last one involved 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.

The National Pork Producers Council contends this new research 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 was always, at best, a guess because there is no reliable data on human uses of antibiotics.

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 U.S. Food and Drug Administration. The team grouped the results in this manner to better inform the discussion on food-animal antibiotics 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."

It’s worth noting that a new NAHMS study will be conducted this year and will offer updated information about pork producers’ antibiotics use. Eric Bush, DVM, with USDA's APHIS, says “it will be interesting to get an updated estimate of antibiotic use” in the 2012 study. “Producers have made a lot of headway. In the last 20 years, technology has helped us reduce antibiotics use.”

To review the study, “Use Estimates of In-Feed Antimicrobials in Swine Production in the United States," go to http://tinyurl.com/7e6lcak.

Guidance 209 began back in June 2010, when FDA released a draft and emphasized that antibiotics be used “judiciously and only when necessary to keep animals healthy.” The driving concern is that subtherapeutic use of antibiotics in animals may contribute to antibiotic resistance challenges for humans. With the release of its final guidance, FDA is saying that subtherapeutic applications do not fall under judicious use.

“The new strategy will ensure that farmers and veterinarians can care for animals while ensuring the medicines people need remain safe and effective,” according to FDA Commissioner Margaret Hamburg.

But not everyone agrees. “The guidance could eliminate antibiotics uses that are extremely important to the health of animals,” says NPPC President R.C. Hunt, a pork producer from Wilson, N.C., “and the requirement for VFDs could be problematic, particularly for smaller producers or producers in remote areas who may not have regular access to veterinary services.”

FDA officials say they will work with USDA to understand the implications of the VFD on underserved areas. FDA also plans to make modifications to the VFD process to make it more user friendly for veterinarians and producers. The VFD requirements are still in draft form, which means there’s an opportunity for comment and guidance, Wagstrom says.

The VFD proposal is “key to all of this,” Carnevale adds. “There’s much work to be done and the devil is always in the details.”

The American Veterinary Medical Association also has formed a steering committee to work with FDA in specifying veterinary oversight provisions in Guidance 209, says Christine Hoang, DVM, AVMA’s assistant director of scientific activities.

FDA officials explain that taking a voluntary approach with companies to eliminate subtherapuetic label claims offers more options. A formal ban would require evidentiary hearings in front of a judge for the numerous drug compounds. It would be a “lawyer-driven process” that could take decades to complete, FDA officials point out.

Steve Kopperud, government affairs counsel for the American Feed Industry Association, agrees. “It is critical this remains collaborative rather than a formal rule-making process,” he says. “It looks like they (FDA) are heading in the right direction.”

But voluntary is a relative term. The guidance does not have the force of law, but you can expect FDA to treat it as such. The agency wants animal-health companies to outline their intentions regarding product adjustments within the next three months and is giving companies three years to work through the process of removing subtherapeutic applications from product labels and moving products to a VFD.

“They (FDA) made it very clear that at the end of three years, if they don’t see adequate progress, they will take further steps to take growth-promotion claims away and make everything a VFD,” Wagstrom says.

While it’s up to individual companies how to proceed, AHI expects that some will pursue new therapeutic claims for products that lose their growth-promotion claims, while other products may be old enough or generic enough that it’s not worth pursuing.

Gaining approval for new label claims will require extensive investment in research trials and data collection. The product will undergo a complete testing and approval process through FDA, assuring that a specific use is efficacious and safe.

Growth promotion, Carnevale explains, is a relatively easy claim to demonstrate during research trials, but proving the efficacy of low-level feed-additive antimicrobials for suppressing subclinical disease can be much more complex.

So, what does this mean to you?

While product applications and availability will change, some products will likely disappear. Depending on your location and situation, your personal access to products also may change. FDA’s guidance could cause hardships for producers running smaller operations and those in remote areas that cannot afford or do not have access to veterinary support to get the required VFDs, Wagstrom reiterates. 

“We will see more sick pigs and higher cost of production,” she adds. “It may translate to higher cost to the consumer, and all of that may happen without any anticipated benefit to public health,” she says.

Wagstrom points to countries where subtherapeutic uses have been banned, such as Denmark’s ban in 2000. That resulted in more sick pigs and an increase in therapeutic use of antibiotics, which typically involve products also used in humans.

This suggests that subtherapeutic use helps suppress and prevent disease outbreaks, along with promoting growth. “We’re very confident that growth-promotion levels have had a disease-prevention impact, which is why we’re concerned about seeing more sick pigs,” Wagstrom adds.

The part that nags at the veterinary and producer sectors about FDA’s new requirements is the lack of scientific evidence tied to risk assessment. FDA is saying there’s a problem with low-level antibiotics in animal feed, but the evidence doesn’t support that conclusion.

“What FDA has ignored is a very large body of peer-reviewed, risk assessments that say antibiotics use in agriculture does not negatively or very negligibly impact public health,” Wagstrom says.

In the end, FDA’s Guidance 209 is going to be a big change, and three years will go by fast. Some product adjustments will come more quickly than others. It will require a period of transition for producers to identify solutions and management strategies to address animal-health challenges. Practices such as vaccination strategies, all-in/all-out pig flow, not commingling pig sources, biosecurity practices and others will be even more critical.

“We see FDA’s new guidance as strengthening the veterinarian/producer relationship,” Wagstrom says. “We have a progressive industry that will adapt and make the changes that we need.”

Antibiotics Use is not a Free-for-all

The common belief among the public that food-animal producers take a carefree approach to antibiotics use and that those products are not monitored with the same rigor as those for human use is far from reality. 

“Antibiotics used in food animals are regulated by the U.S. Food and Drug Administration under the same laws as products for humans are regulated under,” says Ron Phillips, the Animal Health Institute’s vice president of public affairs. He points out that companies have to provide the same kind of proof of safety and efficacy before products are approved as they do for human use. FDA allows four efficacy label claims for antimicrobials:

1. Disease treatment, once a disease challenge has occurred.

2. Disease control, such as during an outbreak, to minimize spread and promote recovery.

3. Disease prevention, when a veterinarian determines an outbreak is likely.

4. Growth promotion, which increases an animal’s weight gain or feed efficiency.

The first three are considered to be therapeutic uses, while growth promotion is a subtherapeutic use. FDA’s new Guidance 209 designates treatment, control and prevention as judicious use and growth promotion as non-judicious use.

“Regardless of the antibiotic, producers and veterinarians must follow the label when administering the product,” Phillips says. “They are very tightly bound to what they can and cannot do.”