The use of antibiotics in food animal production and its possible tie to antibiotic resistance in humans has been in the news recently. Congress received testimony about the issue, and several new laws or regulations are proposed to address it. Progressive Dairyman Editor Walt Cooley discusses how close the national debate comes to the everyday use of antibiotics on dairies with AABP Executive Vice President Gatz Riddell. Q. What is the national debate on the use of antibiotics in food animal production really about? GATZ: At face value, the main debate is about the fear of microbial resistance. And that’s a valid concern because in human medicine it has become a significant issue.

However, the issue of antimicrobial resistance is so incredibly complex that for the public to think you can reduce the use of antimicrobials in one segment and have a significant impact on the overall picture is pretty naïve. We have a public which is, by-and-large, not knowledgeable about common agricultural practices and represented by lawmakers who also may be disconnected from modern agriculture.

A little bit below the surface, I believe, there are significant efforts – either from an animal rights activist’s standpoint or from an anti-technology, anti-modern agriculture standpoint – to try to make a negative impact on animal agriculture. That is the more cynical viewpoint.

Q. Opponents say 71% of all antibiotics used today are used in animal agriculture. Is this true?
GATZ: This is a figure that has been espoused by the Union of Concerned Scientists. It is an invalid figure, yet it’s been a number that has caught people’s attention. It is routinely quoted. The reason it is invalid is that nearly half of the quoted figure represents the use of ionophore antibiotics – such as monensin (Rumensin) and lasalocid (Bovatec) – that have absolutely no impact on human antimicrobial resistance. But this group bulks up that number so they can say, “See how much antibiotics are used in animals?” The number also includes two classes of antibiotics that have been approved for use in the U.S. but have never actually been used in this country.

Q. Much of the buzz around this issue stems from proposed legislation – The Preservation of Antibiotics for Medical Treatment Act (PAMTA). What does it propose?
GATZ: The law proposes to take seven classes of antimicrobials (penicillin, tetracycline, macrolide, lincosamide, streptogramin, aminoglycoside, or sulfonamide) that are currently approved through a fairly stringent FDA regulatory process for use in livestock feed – and within two years of passage, ban their use. During those two years the FDA would be given the mandate to do evaluations on the safety of these products. The FDA simply can’t do that. They don’t have the mechanisms or the resources to evaluate those seven classes of antimicrobials, which could be 40 or 50 different products or labeled uses of products, and do a risk assessment in a two-year time period. So, in effect, were PAMTA to be passed, within two years we would lose a significant number of labeled uses which are critical to prevent and control certain bacterial diseases, such as bovine respiratory disease.

Producers also need to know that the bill talks about therapeutic versus sub-therapeutic uses. The FDA doesn’t currently define uses in those terms. The FDA defines antimicrobial use in one of four categories: treatment, prevention, control or feed efficiency/growth promotion. When this bill bans antimicrobials from sub-therapeutic use, it implies banning them for the use of prevention and control. This doesn’t appear to be consistent with the FDA’s current thinking. Right now FDA’s Guidance Document 209 considers treatment, prevention and control categories all as important. The bill blurs the classic legal definitions found in FDA approvals by introducing its “sub-therapeutic use” language.

Q. The FDA has recently proposed rule changes to its Guidance Document 209, which you referenced earlier. How would these changes impact the dairy industry?
GATZ: It would not have a major impact on the dairy industry. There are no antibiotics feed additives currently approved for use in lactating or dry cows, except monensin (Rumensin). Monensin is not on any of the recognized lists of antibiotics that are important for human medical use, which will be banned under the new rules. So it wouldn’t impact a lactating herd. For replacement heifers there are some antimicrobials that are approved for inclusion in the ration to prevent and control disease, which PAMTA would ban, but the changes to Guidance Document 209 would not. FDA’s draft guidance document just deals with antimicrobials labeled for growth promotion/feed efficiency use that will be banned – few, if any, of which affect the dairy industry.

Q. What does this proposed FDA rule change tell us about future FDA restrictions or approved-label uses for antimicrobial drug use?
GATZ: AABP does not agree that the weight of the evidence supports FDA’s conclusions for banning these antimicrobials. FDA has gone through a whole litany of literature and cherry-picked certain studies that came up with the results that it wanted to portray, tying antimicrobial use to antimicrobial resistance in humans. It could signal a sea change in how the FDA is going to go through its approval processes, looking for consensus documents rather than dealing in science. If it signals a change in the way the FDA does business, it probably does have a much more far-reaching impact than at first-read.

Q. What does this most recent, prominent public discussion about the use of antibiotics in animal production signal for dairy producers and veterinarians?
GATZ: It signals for the dairy industry and for the veterinary profession that we need to step outside our typical routine and talk to the public about the things we are doing that are right. There is a lot of veterinary oversight for antibiotics, and there are a lot of producers that have control mechanisms in place to prevent antibiotic residues. The public doesn’t understand these because they are so far removed from agriculture. We have a real uphill battle, and if we don’t begin to tell our story, we leave it for those that don’t want our story to be told to tell it inaccurately. There are a lot of things that are done right both in animal care and in antimicrobial use, but just a few bad examples tend to be blown up in the media. So it is easy for somebody who doesn’t know about animal agriculture to get the wrong impression.

Q. How should producers and veterinarians respond when someone says, “We need to stop using antibiotics in food production because it’s creating antibiotic resistance in humans”?
GATZ: We believe that we should be able to treat our animals when they are confronted with a bacterial disease, just like humans expect to be treated when they encounter a bacterial infection. Furthermore, we know that there are certain conditions out of our control, such as extreme environmental conditions, that may predispose a group of animal to disease, and if we can prevent animal pain and suffering by treating the group to prevent or control a disease, we think it is important to be able to do so. If there is insufficient scientific evidence that demonstrates that an antimicrobial’s use is contributing to resistance in humans, then why shouldn’t that product be used to make the production of protein for human nutrition more humane, efficient and sustainable? Today, science does not unequivocally show that all uses of antimicrobials in feed are detrimental.

Q. What specifically is your organization doing to address the issue of acceptable use of antibiotics for food animals?
GATZ: For 10 years now we have been involved with the application of judicious use guidelines. We believe that there is already a lot of veterinarian oversight that is not recognized. Granted, antimicrobials used in feed don’t require a veterinarian’s approval, but they probably will two to three years from now, as the FDA’s Veterinary Feed Directive is broadened. But the vast majority of antimicrobials used in livestock feed have veterinary consultation or oversight, and that is the way we think it ought to be.

Q. If you had a magic wand that you could wave over this issue of public perception, what specifically would you change or fix?
GATZ: What I wouldn’t do is tell the public: “Trust us we know what we are doing.” I would take every member of the public and expose him or her to the quality of animal agriculture production in the U.S. today. There are some tremendous examples of how modern agriculture is doing everything right, they are open to the public, and I would like to educate the public on how things are done right.

Q. How would you summarize the misunderstanding that revolves around this issue?
GATZ: This quote, “For every complex issue there is a simple answer which is invariably wrong,” pretty well sums up the issue of antimicrobial resistance. PAMTA’s approach provides a simple answer, which is to ban their use in livestock. The passage of PAMTA would be a political victory, not a scientific statement, and it would have unintended consequences for animal welfare and food safety. PD