Posts Tagged ‘salmonella

Grass-Fed Gas

» June 21st, 2013


Here’s a copy of my New York Times article on grass-fed beef, which ran in April 2012. It’s a distillation from research I’m doing for my book Modern Savage. In a chapter that I recently finished, I demonstrate how the logistics of grass-fed farming won’t even work to ensure this method’s status as niche approach, much less a standard alternative, to raising cattle for food. In this sense, it’s much more detailed than what you’ll find below and what was in my more recent Slate article on Allan Savory. In any case, I had a piece on fish that I was planning to run today (and will likely run tomorrow), but a reader’s comment suggested that I post this piece instead and, as Mountain observed in a recent comment, it’s my blog. Sorry if this post is tedious. If you’re bored, you can always skip back to the “sexism and PETA” discussion, which is still smoldering, from two days ago. 

April 12, 2012

The industrial production of animal products is nasty business. From mad cow, E. coli and salmonella to soil erosion, manure runoff and pink slime, factory farming is the epitome of a broken food system.

There have been various responses to these horrors, including some recent attempts to improve the industrial system, like the announcement this week that farmers will have to seek prescriptions for sick animalsinstead of regularly feeding antibiotics to all stock. My personal reaction has been to avoid animal products completely. But most people upset by factory farming have turned instead to meat, dairy and eggs from nonindustrial sources. Indeed, the last decade has seen an exciting surge in grass-fed, free-range, cage-free and pastured options. These alternatives typically come from small organic farms, which practice more humane methods of production. They appeal to consumers not only because they reject the industrial model, but because they appear to be more in tune with natural processes.

For all the strengths of these alternatives, however, they’re ultimately a poor substitute for industrial production. Although these smaller systems appear to be environmentally sustainable, considerable evidence suggests otherwise.

Grass-grazing cows emit considerably more methane than grain-fed cows. Pastured organic chickens have a 20 percent greater impact on global warming. It requires 2 to 20 acres to raise a cow on grass. If we raised all the cows in the United States on grass (all 100 million of them), cattle would require (using the figure of 10 acres per cow) almost half the country’s land (and this figure excludes space needed for pastured chicken and pigs). A tract of land just larger than France has been carved out of the Brazilian rain forest and turned over to grazing cattle. Nothing about this is sustainable.

Advocates of small-scale, nonindustrial alternatives say their choice is at least more natural. Again, this is a dubious claim. Many farmers who raise chickens on pasture use industrial breeds that have been bred to do one thing well: fatten quickly in confinement. As a result, they can suffer painful leg injuries after several weeks of living a “natural” life pecking around a large pasture. Free-range pigs are routinely affixed with nose rings to prevent them from rooting, which is one of their most basic instincts. In essence, what we see as natural doesn’t necessarily conform to what is natural from the animals’ perspectives.

The economics of alternative animal systems are similarly problematic. Subsidies notwithstanding, the unfortunate reality of commodifying animals is that confinement pays. If the production of meat and dairy was somehow decentralized into small free-range operations, common economic sense suggests that it wouldn’t last. These businesses — no matter how virtuous in intention — would gradually seek a larger market share, cutting corners, increasing stocking density and aiming to fatten animals faster than competitors could. Barring the strictest regulations, it wouldn’t take long for production systems to scale back up to where they started.

All this said, committed advocates of alternative systems make one undeniably important point about the practice called “rotational grazing” or “holistic farming”: the soil absorbs the nutrients from the animals’ manure, allowing grass and other crops to grow without the addition of synthetic fertilizer. As Michael Pollan writes, “It is doubtful you can build a genuinely sustainable agriculture without animals to cycle nutrients.” In other words, raising animals is not only sustainable, but required.

But rotational grazing works better in theory than in practice. Consider Joel Salatin, the guru of nutrient cycling, who employs chickens to enrich his cows’ grazing lands with nutrients. His plan appears to be impressively eco-correct, until we learn that he feeds his chickens with tens of thousands of pounds a year of imported corn and soy feed. This common practice is an economic necessity. Still, if a farmer isn’t growing his own feed, the nutrients going into the soil have been purloined from another, most likely industrial, farm, thereby undermining the benefits of nutrient cycling.

Finally, there is no avoiding the fact that the nutrient cycle is interrupted every time a farmer steps in and slaughters a perfectly healthy manure-generating animal, something that is done before animals live a quarter of their natural lives. When consumers break the nutrient cycle to eat animals, nutrients leave the system of rotationally grazed plots of land (though of course this happens with plant-based systems as well). They land in sewer systems and septic tanks (in the form of human waste) and in landfills and rendering plants (in the form of animal carcasses).

Farmers could avoid this waste by exploiting animals only for their manure, allowing them to live out the entirety of their lives on the farm, all the while doing their own breeding and growing of feed. But they’d better have a trust fund.

Opponents of industrialized agriculture have been declaring for over a decade that how humans produce animal products is one of the most important environmental questions we face. We need a bolder declaration. After all, it’s not how we produce animal products that ultimately matters. It’s whether we produce them at all.

The Amnesia-ville Horror

» June 12th, 2012

Pink Slime!

I’m sick and tired of hearing stories about the disgusting aspects of industrial animal agriculture. I know, I know. It’s important to broadcast these messages—pink slime!, E.Coli! cows eating chicken poop! And, I know, people need to hear the straight dope on factory farming. Still, these stories get on my nerves for at least two reasons.

First, they’re redundant, and their redundancy is alarming. It’s alarming not because the stories themselves are horrific (which they are), but because the muckrakers delivering these messages act as if they’re unearthing some deep dark secret and the consumers hearing the messages act as if it’s never been said before. It’s like we’re living in Amnesia-ville.

Folks! We’ve been bombarded with nauseating narratives about the evils of factory farming for over 40 years. The fact that we have not, as a collective gesture of consumer outrage, monkey wrenched these hellholes into oblivion speaks either to the human tendency to procrastinate or, worse, our pathological indifference.  At some point you have to wonder: are journalists hacking away at this door to no avail?

Well, they may be, as my second point of contention suggests: I despise the way that supposed food activists take these stories and cynically use them to justify a transition to small-scale animal agriculture. This one really galls me because, in making such a suggestion, the so-called activists are doing nothing more than feeding the monster they aim to starve. They fail to realize that all the monster needs to thrive is a cultural acceptance of eating animals. The activists, in their small-farm fetishization, do absolutely nothing to confront this pervasive acceptance. In fact, they only encourage it. In so doing, they encourage factory farming.

We’ll never beat the devil at his own game. Industrial agriculture is not in the least bit threatened when earnest “muckraking” journalists come on the radio or print long stories urging concerned consumers to avoid factory farmed meat in favor of “humanely raised” and “sustainably produced” options. To think the big guys are threatened is a joke. The factory farms will always ensure that the small fetishized farms are never anything more than boutique options for foodies, culinary libertarians, and pin-heads who peck away at their Mac’s in college town coffee shops (oops, that’s me).

The factory farms can ensure their dominance for two simple reasons: consolidation and scale. I don’t like this fact one bit, but it’s a fact—subsidies notwithstanding, it’s cheaper and quicker and more efficient to raise animals in concentrated conditions on a large scale. These measures lead to cheaper animals products and cheaper animal products will, as sure as gravity, lead to the mass consumption of cheap meat. Unless small-scale farms have a plan to upend the most basic principle of classical economics–not to mention human nature–their endorsement of eating animals will continue to be, however inadvertently–an endorsement of factory farming.  They will, of course, deny this.

And they will, of course, be deluding themselves. Worse, they’ll be harming animals. Indeed, their delusions are just as complicit in the senseless killing of billions of animals as are the factory farms they claim to hate so vehemently.  And that gets on my nerves. A lot.


Free-Range Fallacy: The Myth of Safety

» September 22nd, 2011


About two years ago, I published a controversial article in the New York Times suggesting that free-range pigs had a higher risk of contracting trichinosis than confined pigs. My primary source was a peer-reviewed article that had received funding from the National Pork Board. Because the study had been published in a widely respected academic journal, I chose not to mention the funding source. My intuitive sense was that highlighting the industry connection would immediately prevent skeptics from reading further.

Big mistake. The foodie police pounced, the Times printed a shaming “editor’s note,” and I spent much of 2009 contemplating moving to West Texas and living in an underground house.

Lost in all the huffing and puffing over my omission, however, was the gist of the underlying question itself: to what extent are animals raised under free-range conditions prone to contracting diseases that can affect humans? Please understand that the point of exploring this question is not to promote the highly charged thesis that factory-farmed animals are better. Instead, the only goal here is to raise awareness about a method of farming animals that has—primarily on account of its status as a preferred alternative to concentrated animal feed operations (CAFOs)—escaped the critical scrutiny we’ve so dutifully applied to factory farms. The claim that free-range meat is a healthier option is a commonly heard bit of culinary wisdom. For anyone who eats meat, some hard scrutiny should be welcomed.

Since writing my Times piece, I’ve come across considerable research—none of it undertaken with corporate funding—that provides a wealth of information to help us assess the relationship between free-range animal farming and disease. In a study exploring rates of Trichinella and Toxoplasma in pigs raised in the Netherlands, several Dutch microbiologists found that their evidence “indicates that the prevalence of parasitic infections is higher in outdoor farming systems than in indoor farming systems.” An investigation of a Trichinella outbreak in Sardinia (which was long considered free of the disease) observed that the “parasite is restricted to free range pigs.” In Switzerland, a study of free-range pigs and Trichinelli defined “free ranging pigs” as “the group with the highest risk of exposure.” 

Infections seem to intensify in regions of the world that lack adequate sanitation. In a study of free-range pigs in Mozambique, the authors concluded that “free range pig management system represented by far the most important risk factor for porcine cysticercosis”—a disease caused by a tapeworm larva. In Nigeria, pigs “reared by intensive system” had lower rates of bacterial infection than “the population of local pigs on free range.” (Click here for a PDF of the study.)

Poultry has come in for its share of critical analysis as well, at least in the trenches of academic science. A study of Salmonella and free-range (and certified organic) chickens found that 31 percent of the 135 chickens sampled tested positive for the deadly bacteria. The authors were moved to warn that “Consumers should not assume that free-range or organic conditions will have anything to do with the Salmonella status of the chicken” (PDF). An investigation of Taxoplasma gondii (a parasite potentially fatal to fetuses) and free-range chickens in China reported that free-range birds showed an infection rate of 34.7 percent. Caged chickens had an infection rate of 2.8 percent. A similar study undertaken by the USDA’s Agricultural Research Service reported that “A very high prevalence of the parasite (Taxoplasma gondii) was found in chickens raised in backyards (up to 100 %) and free range organic (30-50%) establishments.” It further noted that “overall, prevalence of viable T. gondii in chickens raised indoors was low” (PDF). Swedish veterinary scientists had their findings summarized by a medical news outlet with this headline: “Free Range Chickens are More Prone to Disease.”

Although these studies gained virtually zero media attention, not everyone has ignored their implications. The Humane Society of the United States—an organization fiercely dedicated to issues of animal welfare—put out a report in 2009 acknowledging the many virtues of a well-managed free-range operation. At the same, though, the report frankly admitted that “outdoor flocks may be exposed to wild birds, insects, and other potential infectious agents, and may come into contact with bacteria and intestinal parasites.” It wrote that “Pollorum disease, a type of Salmonella infection, is currently rare in commercially raised chickens, but may occur in backyard flocks.” And it even mentioned that “caged hens are generally protected (from the intestinal parasite Coccidia) by separation from their fecal material.”

It’s time concerned consumers take a page from the Humane Society and look squarely at the research. The idea of a free-range animal is appealing in so many ways. The animals are almost certainly happier. They are also removed from the battery rounds of antibiotics and vaccines that keep them growing in caged systems. They allow consumers to feel better about eating meat. But, as these very recent studies all suggest in one way or another, free-range—however it ultimately stacks up against confined methods—comes with its fair share of problems

Free-Range Logic

» August 15th, 2011

A version of this post appeared in

I fundamentally oppose raising animals for food that humans don’t need. This claim holds true regardless of how the meat is produced or consumed.

I mention this point because the study I’m about to highlight could easily be distorted. The report, published in the February 2011 issue of Foodborne Pathogens and Disease, challenges the perception that intensive animal farming is more likely to spread foodborne pathogens than free-range systems. My choice in drawing attention to this counterintuitive article is decidedly not to argue that factory farms are okay and that we should all go out and support Tyson’s. To the contrary, I want to advance the more radical notion that animal farming in general—whether confined or free-range—is fraught with unique problems that we could easily avoid by not eating meat.

These claims will surely strike food purists as heresy. But Davies’s evidence is compelling.

Two other caveats before I summarize the article. First, although this study took place without corporate funding, the author—Dr. Peter Davies—has accepted support from the pork industry in the past. Whether or not past support skews future research remains an open question, but it’s important to note that the study was published in a peer-reviewed, world-class journal and is based on scores of other studies that found similar results.

And second, I’m well aware that the main concern that jumps to mind when it comes to factory farming is often how low-grade antibiotics use leads to potentially deadly, antibiotic-resistant pathogens. This is undoubtedly a huge problem. But this study addresses only foodborne diseases, and thus so does my analysis. This focus is not meant to dismiss or downplay the pressing problem of antibiotic resistance.

The study in question is an exhaustive analysis of existing evidence on the connection between intensively managed pig farming and foodborne parasites. The article caught my eye because Davies, of the University of Minnesota, attempts something uncharacteristic for an article published in a professional scientific journal. He begins by chiding the mainstream media for its selective reporting on this controversial topic. And not very gently.

“Misinformation in public discourse,” Davies writes, “has achieved pandemic potential with the rise of blogging and other social networking tools.” Discussions of food and agriculture, he continues “are mostly ideological and heavily value laden.” Scientists, he argues, must do more than practice sound science. They must exhort the “scientific community . . . to be more visibly engaged in refuting misinformation as well as presenting new information.” What’s needed is something sorely lacking in so much popular writing about animal agriculture. In essence, “factual accountability.”

Lecture delivered, Davies drops his bomb: “Available evidence does not support the hypothesis that intensive pork production has increased risk for the major bacterial foodborne pathogens.” Nor does it support the opinion “that pigs produced in alternative systems are at reduced risk of colonization with these organisms.” In fact, Davies explains, “pigs raised in outdoor systems inherently confront higher risks of exposure to foodborne parasites.”

These claims will surely strike food purists as heresy. But Davies’s evidence is compelling. Take Trichinella spiralis. This is a nematode parasite that killed thousands of consumers a year in the late 19th century but is extremely rare today. Davies attributes this impressive multi-decade reduction to the improved management practices of modern swine production. Rodent control and regulated feeding practices, he explains, have “practically eliminated the risk of infection.” If a comparison to the 19th century seems disingenuous, note that the 138 cases recorded by the Center for Disease Control between 1997 and 2006 represent a 95 percent decrease in annual infections since the 1940s, and a 76 percent decrease since the 1980s.

During this 10-year span (1997-2006), there were only 15 recorded cases of T. spiralis, nine of which came from commercial pork operations. The other six were linked to “home-raised or direct-from-farm swine.” Given that commercial swine facilities produce 100 times more pigs than free-range systems, these numbers suggest that, on a pig-by-pig basis, there’s “an 80-fold greater risk (per pig produced) of trichina infections resulting from eating niche market versus commercial pork products.” I suppose there are a million ways to quibble with these numbers, but they nonetheless seem consistent with Davies’s larger claim that “it is inevitable that pigs with outdoor access will be at greater risk of Trichinella infection due to exposure to wildlife reservoirs.”

A far more common parasite that Davies addresses is Toxoplasma gondii. It’s likely that a third of us have been laid low by this nasty protozoan, one that accounts for about 75 percent of all foodborne illnesses in the United States. Pork presents the greatest risk of exposure among commercial meats. A 1983-84 national assessment “found that 23% of market hogs and 42% of sows were seropositive for Toxoplasma.” As for the actual presence of Toxoplasma in pork, a 1960s study found a 32 percent rate of infection in pork loins. These are bad numbers by any measure.

Such alarmingly high figures sparked regulators and producers to heighten sanitary measures. By the 1990s, matters had improved considerably. A 1995 study done on confined hogs in North Carolina found one pig among 1,752 that was seropositive for Toxoplasma. More recently a 2008 study of 74,000 market hogs in the United States found a .8 percent seropositive rate. Rates declined, moreover, as farm size increased. The highest rate of prevalence—2.6 percent—occurred on farms producing less than 1,000 pigs per year. Interpreting this data, Davies once again concludes that “the inevitability that pigs with outdoor access will be at elevated risk of Toxoplasma infection is consistently reflected in studies from various countries.”

The story continues with Salmonella. Finding reliable figures on Salmonella prevalence before the onset of large-scale confinement is hard. But, using “convenience sampling,” Davies estimates that Salmonella rates may have been between 27 percent to 78 percent. Today, studies have found rates closer to 7 to 10 percent. And while the correlation between herd size and Salmonella rates is by no means consistent, the most recent examination (2010) of seroprevalence and herd size found that “the odds of being a high seroprevalence herd were three to six times higher for farms with less than 1000 pigs inventory than larger herds.”

Finally, there’s “the most lamentable and preventable public health problem” linked to pork consumption globally, T. solium. Because this parasite thrives where “sanitation is poor and traditional, free-range scavenging pig production is practiced,” it’s not a huge problem in the United States (there were only 221 deaths from T. solium between 1990 and 2002 in the U.S.). But it’s pervasive and deadly throughout the developing world. Davies’s reason for analyzing T. solium is, yet again, to show how “methods of modern confinement swine production virtually eliminate any risks of porkborne transmission of T. solium.” What “endemic countries” must do in order to eliminate the parasite, he claims, is undertake “the simple corralling of pigs.”

Davies’s publication primarily leaves me with two related reactions. The first is why has this study not been in the news? I’m not suggesting that it’s the final word on anything. But should it not be part of a larger discussion we’re having about meat production? No matter how one feels about the findings, they strike me as central to food safety concerns. Can you imagine how the food media would have lit up if a study had found the opposite set of conclusions? (In fact, I waited two months after Davies’s study was published to see if it got any media play before I chose to natter on about it here. Virtually nothing has appeared.)

Davies is equally miffed by the silence, explaining in an email to me that “the absolute absence (as far as I am aware) of any commentary from any groups tending to be critical of modern agriculture is more than a little surprising.” His “hunch” is that his paper has zero “memetic potential in the blogosphere” and, as a result, “does not reinforce the narrative of critics of modern food production and hence has been blissfully ignored.” In my experience interviewing people in agribusiness, I can say with confidence that many, many large-scale farmers feel that their side of the story is never told in the mainstream media.

My second and final reaction is that the study hasn’t seen the light of day because it directly challenges one of the more sacred assumptions of free-range meat. Nobody, especially food writers who make their sympathies public, likes to dice up their own deeply held beliefs. I’m fully aware that there are many other problems with confined production besides zoonotic disease (such as pure cruelty, pollution, and, as noted, the rise of antibiotic-resistant pathogens), but evidence suggesting that one’s chances of getting sick from free-range pork are the same or even higher than with factory-farmed options is fairly damning news for those who advocate smaller, alternative ways of getting pork to the plate.

As I have written here before: “Every study has a counter-study.” I hope readers can debunk Davies’s conclusions. But until they do I’m holding firm to my own sacred assumption that the best way to avoid getting caught in the scientific crossfire between the free-range and confinement options is to simply remove oneself from the battlefield.