The poultry microbiome, once again proving that culture-based ecology misleads us all

Shigella penetrating the intestinal wall. Source: cellimagelibrary.org

If the world was enriched and homogenized, we would actually have a very good idea of what the microbiological community within looks like. Fortunately, the world is much more complex than the miniature environments we culture in the lab, and high throughput sequencing (HTS) is allowing us to fully appreciate micro-biodiversity. As new information becomes available, many of our models for microbial communities continue to be challenged by the actual composition of species in natural environments.

In the world of food safety, we rely on these models to set policy on a regulatory level, and to set critical limits down at the production level. Which tests we run on what products depend directly on what organisms (that cause food borne illness or spoilage) are supposed to be found on that type of food. The authors of this study that came out in PLOS ONE this February examined the microbiome associated with poultry products from farm to fork (meaning from clucking chicken to packaged poultry product) using HTS rather than culture/enrichment methods. The results indicate that there is an unappreciated amount of diversity between different stages of the poultry production process, and that we may not acknowledge the presence of some organisms as much as we should.

In the study, samples were taken from multiple steps in the poultry production process: wet and dry litter, fecal samples, fluid from carcasses collected during the cooling process following slaughter, and fluid from raw retail poultry products (legs, wings, and breasts). Other than the retail portion, all of the samples collected were from the same batch of birds from start to finish. The available RNA from viable cells in each sample was amplified and identified as belonging to specific species using a combination of Illumina sequencing and database referencing (blastn and usearch).

From this pile of data, lists of organisms were compiled to compare the ecosystem profile for each point in production.

The numbers refer the the number of unique taxa found in each group

The authors were very surprised by the amount of diversity between the two litter samples (wet and dry) and the fecal sample. They expected to see very similar profiles, as all of the predicted microbes in those groups would be inoculated from contact with fecal material (young chicks have no inherited microflora, and are coprophagous); however, all of the groups’ microbial communities had very little in common. As shown above, of the hundreds of unique species identified, only 52 were actually found at every stage from farm to fork.

In evaluating food safety, several results are of concern. The first was that the authors found significant amounts of Shigella spp., which have traditionally not been associated with poultry products and may not be a part of many sanitation programs. The second is that in one of their dry litter samples, the authors found a large amount of C. jejuni. It’s presence was interesting as previous studies have found it difficult to cultivate C. jejuni onto dry litter, suggesting that it will not grow in that environment. This discovery further shows that our attempts to cultivate bacteria are not indicative of their behavior in “the wild”. There may be nutrient gradients or a symbiont in play that allows C. jejuni to grow; therefore the possible contamination of dry litter has to be acknowledged in that facility’s Campylobacter monitoring program.

The last point of interest I’ll discuss here is the large amount of unique species that were found in samples following slaughter. This suggests that these species did not come from the farm, but rather were introduced during slaughter and processing. Interestingly, among Campylobacter spp., there was little to no abundance of C. jejuni in the samples, but differing amounts of other Campylobacter spp. This is revealing, as we have been predisposed to expect C. jejuni to be present due to our use of selective media.

Let’s fully appreciate the amount of diversity found within the processing facility, the authors collected two post-processing samples labeled carcass rinse and carcass weep. The rinse was composed of fluid shaken off of the carcass following its removal from the chlorinated chill tanks, and the weep was the drippings from the same carcass 48 hours later. 2/3 of the unique species found the weep samples were not found in the rinse. The authors interpret this as being due to the fact that the sterilization of carcasses is not the goal of poultry processing, and provide the example that viable Salmonella can be recovered from carcasses even after they are sent through the standard antimicrobial processes. The goal is to reduce enumeration, not sterilization.

Finally, in examining the retail samples, we get what we expect. Similar organisms as the weep, with some new faces, presumably because they persisted through processing at undetectable levels, and slowly grew as the product was stored in refrigeration.

The authors conclude by examining some potential symbionts that would allow C. jejuni to persist, but ultimately say that due to the high number of environments C. jejuni can occupy, attempting to exclude it in a universal way will not be very effective.

So all in all, a thorough example of the misdirection we receive from culture bias, and a startling look at how, given enough incubation time, properly processed meat can still support a huge amount of microbial diversity, including many food borne pathogens.

Appreciate this diversity, and make sure you cook your chicken to temperature.

 

ResearchBlogging.org

Oakley BB, Morales CA, Line J, Berrang ME, Meinersmann RJ, Tillman GE, Wise MG, Siragusa GR, Hiett KL, & Seal BS (2013). The Poultry-Associated Microbiome: Network Analysis and Farm-to-Fork Characterizations. PloS one, 8 (2) PMID: 23468931

Why rooster crowing isn’t that impressive, and chickens get jet lag like the rest of us.

Circadian rhythms and jet lag.  There, cyclic crowing behavior explained.

Quite a lot of people are discussing this study from Japan examining the effect of light on the crowing behavior of roosters. The authors observed several birds in experimental conditions where light intensity and duration were controlled, taking observations with audio recorders and cameras. The scenarios presented were a daylight cycle of 12 hours of light and dim light respectively, and constant dim light. Observations were recorded for a period of 14 days, producing this graph.

So many reporters on the study have run with this, making declarations about what great timekeepers roosters are, and how cool it is that they don’t need the sun to know when dawn is.

Well, approximately when dawn is.

“Under dimLL conditions, a free-running rhythm of crowing was observed with a period of 23.7 ± 0.1 h (n = 4), but this free-running rhythmicity gradually damped out”

Interesting, so the sun is unnecessary until it’s been gone for a while, then we start to get some variation. This dampening effect is even more obvious when you place testosterone implants in the roosters.

Testosterone implant roosters calling out “Bro, do you even lift?”

Don’t get me wrong, the fact that Roosters have this accurate of a circadian clock is impressive! It’s very interesting biologically, but it’s not some infallible atomic clock. While many news sites are toting that Roosters are independent of the sun, the opposite is true. Circadian rhythms are directly calibrated primarily by light cycling, with temperature being another important environmental cue. To confirm the roosters knew what time it was, the authors examined the effect of light or recorded crowing sounds at different times of day. They found that there were fewer crowing behaviors at random dawn times than at the “correct time” of day.

This doesn’t mean the roosters know it’s 5pm, but their circadian rhythm is telling them that it isn’t dawn. However, the sun still “came up” so we witness some halfhearted crowing. Anyone who has ever traveled out of their timezone knows exactly how this feels: these roosters have jet lag. While the sun may be coming up, their circadian clocks are telling them that it feels like a different time of day, so they crow in response to the light, but with reluctance and confusion, much in the same way you sleepily get up on vacation when the Louvre opens, even though it feels like 5PM to you.

“But Austin,” you tell me, “aren’t you anthropomorphizing?” While I admit roosters may not empathize with trans-Atlantic vacations, we know that chickens are dependent on daylight to calibrate their biological rhythms because we do it all the time. We increase egg production by simulating summer lighting year round, and alter feed intake in broilers by changing their daylight cycle. We also use this trick to bring mares into heat.

The loss of rhythm observed in 24 hour dim light is likely to become more and more sporadic, and even more so if the roosters were housed singly (as there is some group consensus due to competitive crowing). I would propose that if you could keep the roosters on a light cycle that progressively moved forward an hour a day until dawn was at 2pm, the roosters would crow with the same strict rhythm independent of the actual sun. If the authors of the study choose to pursue this hypothesis, an easy test would be to simply progress their artificial sun’s rise and fall over time.

Alternatively, we could fly several roosters with us to Paris, and see if they wake us up before the Louvre opens.

ResearchBlogging.org

Shimmura, T., & Yoshimura, T. (2013). Circadian clock determines the timing of rooster crowing Current Biology, 23 (6) DOI: 10.1016/j.cub.2013.02.015

Do organic animal operations encourage management decisions that negatively impact animal welfare? Part 3

Here’s the final portion of my paper: Do organic animal operations encourage management decisions that negatively impact animal welfare?

If you’ve missed the other posts, you can check out part 1, part 2,  or read the entire paper here.

 

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Conflict Between the Organic Approach and Welfare Ideals
Despite measures taken to promote prevention, a certain amount of disease is permissible in a healthy ecosystem and the restrictions placed on organic producers by both their certification requirements and ethos can create dilemma’s that could potentially harm animals. Several classic examples of species specific situations have been examined where the animal welfare approach taken by organic producers can be considered detrimental to the animal.

It should be noted that while there is evidence that there is a reluctance to use prohibited medications and chemicals to treat disease on organic farms (Vaarst and Bennedsgaard, 2001), both the Code of Federal Regulations (CFR) and IFOAM standards explicitly state that organic livestock producers must not withhold medical treatment from a sick animal in an effort to preserve that animals organic status (IFOAM, 2005; National Archives and Records Administration, 2012a; Riddle, 2008, 2012).
Dairy
Management of mastitis in organic dairies is a commonly discussed example of when health of the individual and a reluctance to accept the financial loss associated with antibiotic use can potentially harm the animal. Herd health, in general, has not been shown to be significantly different between organic and conventional dairy herds, and some data suggests that the incidence of disease may actually be lower in organic herds, though the reasons for this are unknown (Lund and Algers, 2003; Lund, 2006). Interestingly, the ban on antibiotics for clinical use is more of a concern within U.S. boarders, as the majority of certification standards in the European Union allow antibiotic use to treat clinical disease without jeopardizing the organic status of the animal (Ruegg, 2009). However, the strict FDA guidelines for organic milk production not only prohibit the use of antibiotics in organic livestock, but do not allow the use of any compounds with an antimicrobial effect that are not approved by the FDA for organic production (National Archives and Records Administration, 2012a). Currently, there are zero antimicrobials approved for use in organic animals (Ruegg, 2009). This leaves organic dairy producers extremely limited in their options for treatment when faced with a cow that has mastitis. With few options available, Zwald et al. (2004) were able to find that farmers who switched to organic production began to seek information on treatments from other organic farmers as opposed to veterinarians. This trend is not seen in countries where antibiotic options are available to organic dairy farmers (Hamilton et al., 2006).

So what options are available to organic dairy producers in the U.S.? Once again, prevention is key, but research has shown that rates of mastitis are similar between organic and conventional dairy operations (Lund and Algers, 2003; Lund, 2006). This indicates that treatment must be part of a management plan, even if the organic ethos prevents any attempts to interfere with natural processes through antimicrobial intervention. Certain drugs are available for use on the CFR’s approved substances list with increased withdrawal times to maintain the high standards expected in organic milk production (Riddle, 2008; National Archives and Records Administration, 2012a). These drugs include certain anti-inflammatory drugs that would be useful in treating fever and inflammation associated with mastitis. Beyond pharmaceuticals, therapeutic care including frequent milking is a recognized way to discourage bacterial growth within the affected quarters. Combined with approved anti-inflammatory drugs, frequent milking and supportive care constitutes a common mastitis treatment on organic dairies in the United States (Ruegg, 2009).

Many organic farmers will also attempt to utilize complementary and alternative medicines; however, almost all of the products available have not been evaluated in peer reviewed studies for efficacy. Immunoboost, a USDA licensed immune stimulant sold in the U.S., has been evaluated but has not shown to have any significant effect on the treatment of mastitis (Ruegg, 2009). Other various remedies including peppermint, aloe, and garlic have been utilized by organic farmers as intramammary treatments, however the efficacy of these options is doubted, and their use is prohibited by the FDA (National Archives and Records Administration, 2012a). It appears that without recovery using simple supportive care, any medical intervention necessary to prevent unnecessary pain or distress for non-responsive mastitis cases will result in the loss of a producing animal for that organic operation. This creates a potential welfare risk, as the USDA organic requirements do not specify a point when prohibited treatments must be used, and the decision to discontinue organic treatment resides solely with the farmer.
Poultry
Poultry producers face a distinctive management change when converting to organic as free choice medicated feeds containing antibiotics are commonly used to manage disease and promote growth (Love et al., 2010). Organic poultry is also currently under increased pressure from consumers (Love et al., 2012) to provide a safe and antibiotic free product, which could indicate an increased reluctance to treat conditions using pharmaceuticals. Following the prevention management strategy, organic poultry producers may use a variety of feed supplements including probiotics, prebiotics, organic acids, and plant extracts that have had minimal and sometimes contradictory efficacy reviews (Griggs and Jacob, 2005). Once again, treatment needs to be a key part of the management strategy of the organic producer, and the increased public scrutiny over medication use in poultry has the potential to encourage famers to withhold medication as has been shown in other species (Lund, 2006).

One of the most contested animal welfare debates surrounding organic poultry is regarding the space required by the USDA regulations to remain organic (Kijlstra and Eijck, 2006). While the law only requires year-round access to the outdoors, shade, shelter, exercise areas, fresh air, clean water for drinking, and direct sunlight (appropriate for the species, age, and climate) (National Archives and Records Administration, 2012a); organic farmers have adopted the term “free-range”, which unfortunately like the word “natural,” has no legal meaning. Nonetheless, open access to runs follows the third of Frasier et al.’s welfare ideals in allowing chickens to exhibit natural behaviors and thus have better welfare. The trade-off, however, is that while we have defined the major focus of disease management in organic operations as prevention based, free ranging chickens are more susceptible to predation, outbreaks of cannibalism, parasite exposure, coccidiosis and ascarid infections, and interactions with wild fowl that transmit dangerous diseases such as avian influenza (Verhoog et al., 2004; Kijlstra and Eijck, 2006; Lund, 2006). In order to keep with organic standards, all of these animals must continue to have access to the outdoors, and prohibited pharmaceuticals cannot be fed to treat outbreaks of disease or treat the higher rate of parasites that are found on organic operations (Lund, 2003). Clearly, should there be an outbreak of disease or cannibalism, an ethical dilemma is created between the first two ideals concerning the physical and mental needs of the animal, and the third to maintain natural conditions.

The various dilemmas discussed indicate that organic producers face additional pressure, both financially and in public relations, to avoid the use of treatments that would compromise the organic status of that animal. However, prioritizing animal welfare to include aspects beyond the scope of the clinical health of individual animals can potentially change the way welfare is perceived by conventional farmers and the general public. If an ecocentric rather than an individualistic perspective is considered, and positive experiences can be provided for the animal by indulging its natural behaviors and ecological niche, perhaps some stress events like occasional infections are an acceptable trade-off. Given that a higher incidence of disease has not been found, and that organic producers are required by law not to restrict care to maintain an organic status, it can be determined that organic livestock production does not encourage decisions that negatively impact animal welfare. However, it is recommended U.S. should adopt the EU policy of allowing antibiotics to be used in clinical cases without removing the organic status of that animal. With adequately increased withdrawal times in place to reflect the strict requirements that define organic products and enough consumer education, the organic market should recognize and accept the benefits of this policy change. Livestock would benefit by receiving more aggressive medical intervention as financial pressure not to treat animals could be alleviated as it has been in the EU (Ruegg, 2009), and having prescription antibiotics available as a treatment option could encourage more contact with veterinarians instead of neighbors to discuss animal health. Additional research is needed to support this position that could come from data determining if financial and public pressure are enough to encourage farmers to withhold treatments. In that case, additional actions such as stricter enforcement of the law may be necessary to promote a higher standard of care for organic animals.

New Research: Do organic animal operations encourage management decisions that negatively impact animal welfare? Part 1

For my senior ethics class, I chose to write about an issue everyone has an opinion on, from granola folks at the co-op telling me to watch Food Inc. to farmers complaining about the outbreak of upper respiratory disease from those untreated organic herds sneezing over the fence. I actually ended up changing my own views quite a bit following the extensive research I did, and I really enjoyed writing the paper. I wanted to evaluate the claims often made to me by professors in my land grant school (Oregon State) about the misleading advertizing and hidden evils of organic production, and I wanted to see if there was anything to back up the fanaticism and devotion sometimes projected by organic devotees. This paper is by NO MEANS an exhaustive review of the literature, and I am not qualified to make any official judgement, and is simply meant to be a personal commentary from a recent graduate.

So rather than sit here blathering, the first portion is below, and you can read the full paper here.

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Few agricultural debates come close to generating the same passionate and heated responses that organic farming seems to elicit. The discussion surpasses the interests of producers with conflicting ideologies to be hotly debated by assertive consumers as well; people who highlight the paradox created by their interest in the safe and responsible production of their food, while avoiding all involvement in its creation. The originally proposed Organic Foods Production Act of 1990 received nearly 300,000 comments on the proposed requirements, more than any other piece of legislation in history (Vos, 2000). Clearly this indicated that the role organic farming played in food production was extremely important to U.S. citizens then, and continues to be a relevant topic as organic operations have grown by 40-50% every five years since 1992 (USDA, 2010).

The general public also has a strong interest in the way animals are managed, especially when management techniques play a role in the health or well-being of the animals prior to their use for meat, milk, or eggs. Humane management is often brought up when discussing the merits or flaws of organic operations, and is extremely important to producers due to the important role animal welfare plays when consumers make purchasing decisions. Prickett et al. (2010) found through the use of a telephone survey that 49% of consumers consider the well-being of farm animals when purchasing meat, and 83% of consumers disagree that lower prices are more important than the well-being of the animals used. These numbers become critical when organic producers need to justify the increased cost of their products and conventional producers are forced to avoid the alternate impression that their animals are treated poorly.
Marketing pressure placed on both groups leads to a vicious back and forth of both valid questions and vague accusations, among which is the suggestion that organic farms can act as reservoirs of disease (Kijlstra and Eijck, 2006). One mechanism for this accusation could be the avoidance of chemical or synthetic intervention for pest control and treatment of disease. This paper seeks to evaluate organic farming ideologies and legal constraints that create ethical dilemmas surrounding animal welfare, and determine whether organic management encourages decisions that are detrimental to the animals involved.

Animal Welfare and the Organic Movement
Early organic movements were created with the goal that a more sustainable and environmentally friendly farming system could be created that would benefit not only farmers and consumers of organic products, but also the animals within this system (Lund, 2006). These ideals have persevered and are a common talking point in promotional materials that market organically raised animals as drug and chemical free, and much closer to a “natural” condition (Riddle, 2005). This concept of “natural” is commonly used to differentiate organically produced animal products from conventional ones.

Utilizing the word “natural” creates an issue of perception; while the public widely accepts “natural” as a product descriptor, the word itself has no legal definition when used in food advertizing or packaging in the U.S. However, consumers have been shown to associate descriptions of “naturalness” not only with animal welfare but sustainability and care for the environment (Verhoog et al., 2003). While this may imply a scheme to sway consumer loyalty, the word is widely accepted by organic producers as an accurate descriptor to differentiate organic methods from conventional. While “natural” can have broad definitions like including the entire universe or everything untouched by man (thus either removing agriculture or providing no distinctions in practice), Verhoog et al. (2004) were able to show that organic producers feel organic can be classified as more natural than conventional agriculture as its aim is to be harmoniously integrated into nature. In this way nature is seen as a teacher or model for sustainable and humane agriculture. This ethos pushes organic farmers into an ecocentric approach when making management decisions. From this perspective, we begin to see how organic farmers may view welfare differently than conventional farmers or veterinarians.

Read the rest of the paper here.

 

ResearchBlogging.org
Vonne Lund, & Bo Algers (2003). Research on animal health and welfare in organic farming—a literature review Livestock Production Science, 80 (1-2), 55-68 : 10.1016/S0301-6226(02)00321-4

Newsworthy: University of Georgia is characterizing flock vocalizations as a stress indicator.

Hey all, taking a quick break from blogging as I’m busy with a personal research project I’ll report here on ASR soon, but I wanted to add a quick post for anyone subscribing to RSS or wondering if I’m still alive.

This article on ScienceDaily details a study going on at the University of Georgia, in which they’re recording flock vocalizations to find distinct patterns that can be associated with temperature levels, ammonia concentrations, and other detrimental environmental factors. This has possible implications not only for the welfare of the birds but for the efficiency of the operation.One example of a financial incentive that the article provided is that current ammonia detectors are expensive and short-lived, and if a computer instead could “listen” to the flock and identify specific vocalization changes related to ammonia levels those detectors could be made obsolete.

It’s a cool article, and an awesome example of how agriculture continues to keep up with technology. Check it out and I’ll be back to regular posting as soon as my other personal project is on it’s way!

Banned antibiotics in feather meal – A discussion with an author of the study

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

Newsworthy: Banned antibiotics found in feather meal at Johns Hopkins – How did they get there, and why does your press release contain different conclusions?

An article recently published in Environmental Science and Technology details a study conducted at Johns Hopkins where when examining samples of commercially available feather meal (used as a protein supplement feed or fertilizer) they found trace amounts of fluoroquinolones, a class of antibiotics that have been banned for use in animal feed for 6 years. This is an interesting find, and definitely warrants further research before any broad sweeping conclusions can be made. You know…unless you publish a press release condemning the entire industry for breaking the law and trying to kill us all (question, if all the chicken consumers are dead, how does that lead to higher profits?).

The article itself is very well done. The authors collected samples of feather meal from several states and Canada and tested them for various pharmaceuticals. They also autoclaved the samples to see how the heating processes involved in creation of the product affected degradation/digestion of any of the compounds, and exposed E. Coli cultures to the meal to see if the presence of one or more of the compounds was enough to select for antibiotic resistant populations (they were).

The researchers examined each of the compounds of interest and proposed mechanisms for their presence. Some of them are used at various levels legally within the industry, and the presence of many others (such as caffeine) can be explained by their introduction through various feedstuffs (such as coffee pulp and green tea powder) (Love et al., 2012).

Obviously of most interest to the researchers were the levels of fluoroquinolones, and they hesitantly proposed possible mechanisms for their introduction into feather meal.

“Fluoroquinolones (enrofloxacin, norofloxacin, or ofloxacin) were detected in 6 of 10 U.S. samples, which was not expected because fluoroquinolone use in U.S. poultry production has been banned since 2005. These findings may suggest that the ban is not being adequately enforced or that other pathways, for example, through use of commodity feed products from livestock industries not covered by the ban, may inadvertently contaminate poultry feed with fluoroquinolones…To better interpret our findings, corroborating evidence in the form of antimicrobial usage practices and dosing amounts would be needed.” (Love et al., 2012)

Clearly we’re not ruling out the possibility of these antibiotics being fed, but there is no cause and effect relationship here. They also make note that feather’s contain antibiotics in higher concentrations than meat or other tissues, even after legally defined withdrawal times to remove them from edible tissue. The conclusions here are justly cautious, and place no blame or accusations upon the industry.

The other interesting find was that the feather meal tested would select for antibiotic resistant strains of E. Coli when exposed to cultures. However, this was only testable with autoclaved samples of the meal. And did we mention that the only samples tested here were sourced from China (who according to the article use many more antibiotics than we do in poultry production)?

“These initial results suggest, but cannot prove, that the inhibiting substance may be an antibiotic/bacteriostatic. Autoclaving may have attenuated the quantity and bioavailability of antimicrobial drugs originally present.” (Love et al., 2012)

Again, a cautious observation and hardly conclusive. Comparisons were made from standard cultures exposed to low levels of relevant antibiotics to see if the same strains were removed, but this data cannot be correctly compared as the feather meal was not controlled enough to isolate those compounds. The authors finish their discussion with an appreciation for the novel information they found and an invitation for others to verify, replicate, and build upon their results.

“We have previously described risks related to administration of medicated feed to food animals, which may promote selection for antimicrobial resistance. The presence of antimicrobials in feather meal, as determined in this study, is a previously unrecognized source of these drugs in animal feed. Because this is the first study of PPCPs in feather meal, we invite independent verification of our results by others. More work is needed to determine whether the detected levels of PPCPs in feather meal have an impact on the quality of food animal products and the safety of consumers.” (Love et al., 2012)

And there we have it, an exciting new study that presents a lot of questions to be used for follow-up research. So we’ll publish it and make sure to put out a press release so that not only those keeping up with the journals can read and understand what we’re currently researching.

Well…it seems like the authors like to be scientific when submitting journal articles, but prefer big headlines and sensationalizing when trying to popularize their research. In their official press release, these researchers quickly turn from cautious scientists to industry whistleblowers.

“The discovery of certain antibiotics in feather meal strongly suggests the continued use of these drugs, despite the ban put in place in 2005 by the FDA…The public health community has long been frustrated with the unwillingness of FDA to effectively address what antibiotics are fed to food animals.” – David Love, PhD

Comments from Keeve Nachman, PhD, show a level of conviction that I had no idea he possessed in the original article.

“In recent years, we’ve seen the rate of fluoroquinolone resistance slow, but not drop…With such a ban, you would expect a decline in resistance to these drugs. The continued use of fluoroquinolones and unintended antibiotic contamination of poultry feed may help explain why high rates of fluoroquinolone-resistant Campylobacter continue to be found on commercial poultry meat products over half a decade after the ban.” (I guess we know for sure they’re still being used in the US, I must have missed that citation in your introduction)

“A high enough concentration was found in one of the samples to select for bacteria that are resistant to drugs important to treat infections in humans” (Note: the concentration comment is true, however, your study stated that there was not controlled enough testing to prove that any specific compound present caused the bacterial selection)

“We strongly believe that the FDA should monitor what drugs are going into animal feed…Based on what we’ve learned, I’m concerned that the new FDA guidance documents, which call for voluntary action from industry, will be ineffectual. By looking into feather meal, and uncovering a drug banned nearly 6 years ago, we have very little confidence that the food animal production industry can be left to regulate itself.”

Wow, this press release from the actual authors of the article must be legit, after all, they wrote it, and they wouldn’t write/act completely differently so as to both dangle a carrot to the media and still get their research published in a peer-reviewed journal right?

I knew the Colonel was lying to me. Source: kfc.com

Well, the press release did its job, and Nachman can be found interviewing left and right about how he was “floored” by the result, and how that the more he learns, “the more [he is] drawn to Organic”. There’s a severe lack of integrity here, and the misrepresentation of your data and analysis to cater to anti-big-Ag sentiments is irresponsible and unethical.

So, future scientific corespondents for the Daily Mail aside, what are some other proposed mechanisms for the presence of these banned antibiotics? After all, I’m suggesting that they aren’t being fed routinely as the authors apparently really believe. Let me rephrase that, I’m not ignoring multiple unproven mechanisms for the purpose of shock science.

I spoke with James Hermes PhD, a professor and Poultry Science Extension Specialist here at Oregon State University, about the article. He had obviously heard of it and shared with me some discussions he had had with his colleagues. Their proposed mechanism for the introduction of the pharmaceuticals was through groundwater.

“Feather meal is boiled at the rendering plant, it’s processed with a lot of water, so anything in the groundwater can end up in the meal…Just recently near [Corvallis] they did some testing and found nearly everything we use at home. For years they told us to flush our excess medications…It’s always been there, we’ve just only recently been able to look at such small concentrations 1 parts per billion, trillion, or even possibly quadrillion.” – James Hermes, PhD

So in addition to whatever chickens could be exposed to via drinking the water and concentrating pollutants in their feathers, additional water and pollutants are introduced during the rendering of the product. He encouraged me to find some research showing that ground water contains any and all of the things discovered in the feather meal, and I found it.

So is this a possible mechanism for the introduction of these contaminants? I suggest the authors of the study follow their own advice in the article and explore this mechanism. Perhaps see if the levels of the pharmaceuticals change in the feathers both prior to and after rendering/boiling, explore if they are present in organically produced feather meal, and find out if there are still large concentrations of fluoroquinolones in the groundwater of the areas processing feather meal. And hey, if they want to keep on trucking with scare tactics, I think finding this stuff in the water supply will be much more frightening to the public given that we can’t buy organic water (don’t start).

Finally, in evaluating consumer exposure to the present antibiotics in feather meal, we should keep in mind the steps necessary in the shortest route to the consumer. First, there have to be high concentrations of antibiotics in feather meal; second, that feather meal must be fed to an animal used for food, third; those antibiotics must be retained and remain active until slaughter of that animal at a high enough concentration; fourth, they have to survive gastric juices and be absorbed into the small intestine of the person eating the meat/milk. Nevermind that along the way, the authors of the relevant study note that at any point the vector for the antibiotics is heated most of them will degrade.

Obviously, if the feather meal is used as fertilizer instead of a by product feed, then there are a few more steps that need to take place to get those pollutants onto the plate.

Now if you’ll excuse me, I need to finish this compelling article on how those fat cats selling nautral almond extract are trying to murder me .

 

ResearchBlogging.org
D.C. Love, R.U. Halden, M.F. Davis, & K.E. Nachman (2012). Feather Meal: A Previously Unrecognized Route for Reentry into the Food Supply of Multiple Pharmaceuticals and Personal Care Products (PPCPs) Environmental Science and Technology, 46, 3795-3802

Kolpin, D., Furlong, E., Meyer, M., Thurman, E., Zaugg, S., Barber, L., & Buxton, H. (2002). Pharmaceuticals, Hormones, and Other Organic Wastewater Contaminants in U.S. Streams, 1999−2000: A National Reconnaissance Environmental Science & Technology, 36 (6), 1202-1211 DOI: 10.1021/es011055j

 

 

Update: following this post I had a chance to talk with one of the Authors of the article, read about our discussion here.

The Craigslist Hermaphrodite Chicken

That caught your attention, didn’t it? I’ve been watching Craigslist every day because I want to add two more chickens to my flock and if anyone puts them on there for free you’ve got to nab them quick. I haven’t had much luck since spring ended on nabbing free layers (roosters are a dime a dozen), but I came across this posting that made my jaw drop. Here’s the text for when the post is taken down.

Ameraucana chicken (albany)


Date: 2011-06-20, 5:54PM PDT
Reply to: sale-4zguk-2452639946@craigslist.org [Errors when replying to ads?]


 

True hermaphrodite chicken
Bought at the state fair last year as the first place lavender ameraucana pullet

later laid a too large egg that damaged an ovary.. which became a testical…1 in 1000 chance
began to grow cox comb and spur buds.
still lays a nice greenish blue egg now and then but thinks she is a rooster which she now is also.(can fertilize other hens but not itself)
A chicken no one else you know will have! Beautiful coloring, again she won first in her class at state fair last summer.

Nice and my kids will miss very much but our primary rooster wins out. though they get along great and s/he’s a great conversation piece I can’t afford an extra chicken that doesn’t pull the weight it was meant for.

Bought for more but will sell for $20
email if interested
pic from when brought home from fair last sept. also the only chicken not afraid of dogs. will just peck at their noses till they back off

  • Location: albany
  • it’s NOT ok to contact this poster with services or other commercial interests

___________________________________________________________________________________________

Yeah. I figured this guy was off his rocker. But, as I don’t really know all that much about chickens, I shot an email to my reproduction professor from last term, Dr. Fred Menino.

“Hi Dr. Menino,

I came across this craigslist ad that seems…like questionable information. I can’t see how any hermaphrodidic chicken would actually be a result of a “damaged ovary” and spontaneously become a fertile testicle. Espicially considering the other ovary is essentially non existant and he claims it still lays eggs. Are any of the claims made here possible in any way? Or is this guy completely off his rocker? I’d appreciate the insight or hopefully give you a laugh.”

He got back to me very quickly, and kind of blew me away.

“HA!!! Hi Austin!!! Good to hear from you!!!

This is like something you would read in the National Enquirer….BUT, believe it or not, there is a physiologic basis for some of the things this poultry entrepreneur is talking about!!! There is a phenomenon known as the “ambisexual versatility of the bird”…..I attached a link. I used to talk about it in ANS 316 but the poultry classes pick this up (I think?!) so I dropped it from my class.

http://www.myoops.org/twocw/tufts/courses/5/content/215765.htm

Anyway, birds are weird………if you do certain manipulations to a hen (genetically female), you can alter her phenotype: 1) if you remove the left ovary before 20 days of age, the right ovary will develop into a functional testis and produce androgens and sperm. The hen develops rooster-like qualities but there’s no male ductwork leading to the cloaca!!! 2) if you remove the left ovary between 20 days of age and sexual maturity (18-20 weeks of age), the right ovary will develop into an “ovatestis”, an organ which has both follicles and seminiferous  tubules!! 3) lastly, if you remove the left ovary after sexual maturity (18-20 weeks of age), the right ovary will develop into a functional ovary, however, it will lack the oviduct to connect to the cloaca.

The question with this guy’s chicken is:  if the damage to the left ovary occurred before sexual maturity and an ovatestis developed, could sperm and/or eggs, as he suggests, be shed into the rudimentary oviduct that would be present?? I guess anything’s possible….maybe I should buy it and do a necropsy to see what the heck is going on??!!!!

Take care,

Fred”

I had half a mind to take him up on that offer and buy the bird just to study it and assist in that necropsy. I wonder how the poster would feel about that, maybe I would leave that part out. This bird is just weird, super cool, but weird. The very idea of a sexual genotype producing a viable opposite phenotype is remarkable, and kind of breaks a lot of rules biologically. Though I’m sure there are dozens of similar or stranger things like this in the animal kingdom, but outside of weird marine life, I’ve never heard of anything like this before.

Here’s a wild sci-fi thought though, what if we could someday manipulate this so that we could breed chickens that are self-fertilizing, and would only produce gametes with XX so that we could create a self-cloning layer breed. Then we wouldn’t have to destroy all the useless males produced in our industry layer breeds! There would be a dangerous loss of genetic diversity within the stock, and they would be extra susceptible to being wiped out by disease or anything tailored to them, but the idea is exciting. No doubt they’ve tried it somewhere along the line. The real marketing question though, is that while animal rights groups would be (hopefully) satiated with no longer having to destroy male layer chicks, would the public accept and purchase eggs from genetically manipulated hermaphroditic birds?