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Following my recent post where I examined an article from Johns Hopkins that found multiple contaminants in commercial feather meal (including fluoroquinolones, a class of antibiotics that have been banned from use in poultry since 2005), I was honored to be contacted by one of the Authors, Dr. David Love. Dr. Love offered to continue the discussion with me, and was happy to answer my questions regarding the study, the media frenzy it has inspired, and some of the goals of the research conducted at the Center for a Livable Future. I immediately jumped at the chance, and was able to speak with him on the phone earlier this week.

As those who read the post last week have seen, my primary concern with the study was not to do with it’s results or conclusion, but in how the press release was worded. He didn’t feel that it was as misrepresentative as I initially interpreted it, and we quickly moved on discussing just why this article was picked up so quickly.

“I’m not sure how much more clear it could be, we specifically said feather meal, and the title of the study says ‘feather meal, a previously unrecognized route for reentry into the food supply’…I think on the whole we were careful, I don’t think we can come out of this paper with twelve samples and make sweeping generalizations, it’s important to point out that our big recommendation of the study in the last line was that more research should be done…It’s really at the intersection of the media and what they’re interested in, the consumer and what their interests are, and then our story as the authors. Consumers are so interested in what’s going on with their food. We say we did a study on chicken, there’s energy there, and if that’s what they want to talk about, it tells me that we need more transparency in packaging, labeling, and more consumer education. “

I agree, everyone is interested in what they eat, and he makes a great point that we shouldn’t ignore that interest as scientists or producers as it reflects consumer demand. Another point I wanted clarification on was the statement that self-regulation and our current FDA guidelines aren’t sufficient to keep contaminants out of food.

“From the looks of the latest FDA Guidance there’s a lot of strong language, but no teeth in the language. I think for the draft guidance for 213 we’re hopeful, as there will be a larger role for veterinarians in prescribing antibiotics. As for self regulation, I would be more willing to support it if there was more transparency. Many other countries go out of their way to report use, and we in the U.S. have trouble dividing up which antibiotics are used for growth promotion, prophylaxis, and therapy. It would be hard to go about but if we could get that, and reduce or cut growth promotion uses, we would be able to actually measure progress on how we’re reducing antibiotic use in animals.”

He made a very strong point, and following publishing my post last week I came upon  a commentary published by the authors discussing the issue created by unintentional overuse of antibiotics in feed. The article actually provided many of the citations supporting their arguments that I mockingly asked for last week, and I encourage anyone interested to check out the data behind the conclusions. In wrapping up our discussion, I asked where the authors planned to go next with follow-up research.

“A lot of people want to know. Well we found this stuff in feathers, now lets look at meat, at the consumer level with what you buy at the grocery store.”

A logical next step, and one that I’m sure will have even more interest than the findings from feather meal.

Out of our discussion, I discovered a different perspective of the research that I believe was reflected in the discussion, but was completely missed by the media and myself. While the source of the contaminants is obviously a big question, that wasn’t the purpose of the study. The authors were examining feather meal as a route to antibiotic introduction that could have implications in terms of creation of AB-resistant bacteria. Regardless of how it got there (like through contaminated groundwater, as I suggested), a small percentage of chicken producers use it as a feed supplement, thus introducing fluoroquinolones into our food supply through a previously unknown method, and thus not subject to withdrawal times that prevent meat contamination. Further exploration of this research goal will probably concern testing the meat of chickens being fed feather meal for the presence of fluoroquinolones, and seeing if they do allow a sufficient amount to reenter the food supply that may warrant a withdrawal period.

In reflecting on my first post on the subject, I believe that my own response to the press release provided an excellent example of the point I was making. As this case and my interpretation of it reveal, it’s extremely easy to think that your statements were clear and representative of the science at the time, but under outside scrutiny can still be misinterpreted whether in a press release or a blog post. I’m sure I’ll remember this article when I get to publish my first paper, and take a good, hard look at the press release before approving it.

 

 

I want to sincerely thank Dr. David Love for taking the time to speak with me about his research, food safety, and agriculture research in general. I greatly enjoyed our discussion and hope that I get to work with him again. Quotes used in this post are transcribed from my notes I took during our discussion, and are used with his prior review and permission.

If you are still interested in this topic I encourage you to read all you can about it, there’s no end to the depth of the science and social issues involved. I’ve linked to the original article several times, but you can also read the supplementary material here that includes some of the anecdotal evidence in support of the presence of some of the contaminants. You can also read the National Chicken Council’s response to the NY times opinion piece that first made this research so popular. Finally, here’s some research from Chile correlating concentrations of enrofloxacin (a fluoroquinolone)  in feathers with withdrawal times in chickens treated with the drug.

Additional government resources on AB-resistant bacteria statistics and USDA residue testing: FDA NARMS report and USDA Redbook.

Please feel free to leave comments on how you feel about the research, the media presentation, and my own interpretation! I know for a fact all you people from ResearchBlogging.org have opinions, I read them all the time!
ResearchBlogging.org

Love, D., Davis, M., Bassett, A., Gunther, A., & Nachman, K. (2010). Dose Imprecision and Resistance: Free-Choice Medicated Feeds in Industrial Food Animal Production in the United States Environmental Health Perspectives, 119 (3), 279-283 DOI: 10.1289/ehp.1002625

Love, D., Halden, R., Davis, M., & Nachman, K. (2012). Feather Meal: A Previously Unrecognized Route for Reentry into the Food Supply of Multiple Pharmaceuticals and Personal Care Products (PPCPs) Environmental Science & Technology, 46 (7), 3795-3802 DOI: 10.1021/es203970e

San Martín B, Cornejo J, Iragüen D, Hidalgo H, & Anadón A (2007). Depletion study of enrofloxacin and its metabolite ciprofloxacin in edible tissues and feathers of white leghorn hens by liquid chromatography coupled with tandem mass spectrometry. Journal of food protection, 70 (8), 1952-7 PMID: 17803156

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One Response to “Banned antibiotics in feather meal – A discussion with an author of the study”

  1. This was a really nice read! I commend you for posting about an important topic and not being afraid to criticize, and also for being willing to change your position when provided with a new perspective. And kudos to Dr. Love for neither ignoring you nor for striking out at you but for contacting you to initiate a friendly discussion.

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