E. Coli and the acid rumen

Fork and spoon on salad

This blog has previously considered the relationship between antibiotic resistant bacteria and factory farming. Recently, I learned about another way in which industrial meat production is breeding microbes that kill humans all the more efficiently. This one has to do with the acidity of our stomachs, one of the ways in which our bodies protect themselves from microorganisms living in the food we eat.

A cow living on a diet of grass has a rumen with a neutral pH. The rumen is the ‘first stomach’ of grass eating animals. Inside, bacteria help to ferment undigestible grass into material the cow’s body can process. Along with these digestive bacteria, many other kinds are present. One sort – Escherichia coli – kills humans by releasing toxins that destroy the kidneys. ‘Normal’ E. Coli, of the sort found in cows since the 1980s, cannot tolerate an acidic environment. As such, our stomachs are pretty good at killing it and thus keeping it from killing us.

A cow in a factory farm does not eat grass. The corn it eats creates an acidic environment in the rumen. This makes the cows ill, while also helping to breed E. Coli that can survive passage through acidic human stomachs. Now, about 40% of feedlot cows have E. Coli in their rumens. Feeding them grass or hay for a few days before slaughtering reduces the number of E. Coli in the animal’s digestive tract by about 80%, but factory farms do not do this. Instead, they try to prevent E. Coli outbreaks through irradiation.

Just another way in which industrial meat farming perverts nature and threatens human health.

[Update: 22 January 2010] Apparently, new research has called this hypothesis about diet and e. coli into question: “different set of findings emerged to indicate that this particular strain did not, in fact, behave like other strains of E. coli found in cattle guts. Most importantly (in terms of consumer safety), scientists showed in a half-dozen studies that grass-fed cows do become colonized with E. coli O157:H7 at rates nearly the same as grain-fed cattle. An Australian study actually found a higher prevalence of O157:H7 in the feces of grass-fed rather than grain-fed cows. The effect postulated (and widely publicized) in the 1998 Science report—that grain-fed, acidic intestines induced the colonization of acid-resistant E. coli—did not apply to the very strain of bacteria that was triggering all the recalls.”

Author: Milan

In the spring of 2005, I graduated from the University of British Columbia with a degree in International Relations and a general focus in the area of environmental politics. In the fall of 2005, I began reading for an M.Phil in IR at Wadham College, Oxford. Outside school, I am very interested in photography, writing, and the outdoors. I am writing this blog to keep in touch with friends and family around the world, provide a more personal view of graduate student life in Oxford, and pass on some lessons I've learned here.

18 thoughts on “E. Coli and the acid rumen”

  1. Just another way in which industrial meat farming perverts nature and threatens human health.

    Does feeding cows corn really ‘pervert nature?’ It seems a bit harsh to say that it does.

  2. On its own, perhaps not. But the feeding of corn to cattle is just one important element of the industrial foodsystem that I am objecting to here. If you want to read a compelling argument against it – including an effective criticism of the unnaturalness of corn feeding – please read Michael Pollan’s excellent book The Omnivore’s Dilemma. I should be posting a review on this site within the next few days.

  3. I find it hard to believe that a standard of “non factory farming” could not be accredited, and the meat sold with a trust-able label. It would then be very easy to eat less perverse meat products, in the same way as it is now (reasonably) easy to get organic vegetables.

    Perhaps such a standard is already in place and enforced and I am merely ignorant of it. However, Milan, your worry seems often that it would simply be too difficult to know?

  4. ‘Organic’ means very little in North America, as does ‘Free Range.’ Governments just aren’t willing to set the bar at a level that would annoy the factory producers. As such, ‘free range’ and ‘organic’ factory farms differ little in substance from the ordinary sort.

    If E. Coli is your main worry, you can buy directly from local farmers who feed grass to their animals.

  5. “Generally speaking, free-range eggs come from chickens who have some access to the outside, but how much access? The U.S. regulates the use of the term on chicken but not on eggs, and doesn’t stipulate how much outdoor time is required. Canada regulates neither. No other criteria, such as environmental quality, size of the outside area, number of birds, or space per bird, are included in this term. Typically, free-range hens are debeaked at the hatchery, and have only 1 to 2 square feet of floor space per bird. The birds may or may not have litter and access to nests and perches.”

  6. “In Canada, the government has published a national organic standard, but it is a guideline only; legislation is in process. Certification is provided by private sector organizations. In Quebec, provincial legislation provides government oversight of organic certification within the province, through the Quebec Accreditation Board (Conseil D’Accréditation Du Québec).”

  7. Canada’s New Government Certifies Organic Choice for Consumers

    BARRIE, Ontario, July 21, 2007 – The Honourable Chuck Strahl, Minister of Agriculture and Agri-Food and Minister for the Canadian Food Inspection Agency (CFIA), today presented the new Canada organic logo at the Barrie Farmer’s Market. The logo, which is a part of the new Organic Products Regulations announced in December 2006, will tell consumers that they are purchasing products that are federally certified as organic.

  8. Canada’s Organic Products Regulations (OPR)

    The regulation is expected to take two years to implement (to December 2008). The government will begin by appointing accreditors for the certification bodies working in Canada. The certification bodies will then need to be accredited and demonstrate that they are ready to certify to the Canada Organic Standards (see link below).

  9. Organic Production Systems General Principles and Management Standards (PDF)

    Livestock Living Conditions

    6.8.1 The operator of an organic livestock operation shall establish and maintain animal living-conditions that accommodate the health and natural behaviour of all animals, including

    access to the outdoors, shade, shelter, rotational pasture, exercise areas, fresh air and natural daylight suitable to the species, its stage of production, the climate and the environment;

    access to fresh water and high-quality feed in accordance with the needs of the animal;

    sufficient space and freedom to lie down in full lateral recumbency, stand up, stretch their limbs and turn freely, and express normal patterns of behaviour;

    space allowances appropriate to local conditions, feed production capacity, livestock health, nutrient balance of livestock and soils, and environmental impact;

    production techniques that foster the long-term health of livestock, especially where animals are required to provide a high level of production or rate of growth;

    appropriate resting and bedding areas in accordance with the needs of the animal;

    livestock housing shall have non-slip floors. The floor shall not be entirely of slatted or grid construction. Buildings shall have areas for bedding and resting that are sufficiently large, solidly built, comfortable, clean and dry. They shall be covered with a thick layer of dry bedding that can absorb excrement. Where bedding material is typically consumed by the animal species, it shall conform to the feed requirements of this standard;

    the outdoor stocking density of pasture and runs shall be low enough to prevent soil degradation by the livestock and overgrazing of vegetation.

    Livestock – Indoor Space – Outdoor Space

    Adult cows – 6 m^2 per head – 9 m^2 per head

    Growing pigs – Incremental increase from 0.6 m2/head at weaning to 1.3 m2/head at finishing or breeding size – Incremental increase from 0.4 m2/head at weaning to 1 m2/head at finishing or breeding size

    Broilers – 10 birds/m2 – 4 birds/m2

  10. I think it’s even essential to have some E. coli in your gut, as long as it’s not the pathogenic strain. E. coli is part of the normal bacterial flora of the intestine. It serves the production of vitamin K and also limits the growth of other more harmful types of bacteria.

  11. E. coli is part of the normal bacterial flora of the intestine. It serves the production of vitamin K and also limits the growth of other more harmful types of bacteria.

    Escherichia coli (E. coli), is a bacterium that is commonly found in the lower intestine of warm-blooded animals. Most E. coli strains are harmless, but some, such as serotype O157:H7, can cause serious food poisoning in humans, and are occasionally responsible for costly product recalls. The harmless strains are part of the normal flora of the gut, and can benefit their hosts by producing vitamin K2, or by preventing the establishment of pathogenic bacteria within the intestine.

  12. Meat Wagon: Cow-feed misdeeds
    More trouble with ethanol waste as cow chow

    The government-mandated spike in ethanol production has made corn a pricey luxury for feedlot operators. To cut costs, they’re scrambling to substitute scarce corn for abundant distillers grains — the mush that’s left over from corn after the ethanol process.

    For every bushel (56 pounds) of corn ethanol makers suck in, they spit out about 18 pounds of distillers grains. And as ethanol production has ramped up — from 2.1 billion gallons in 2002 to an expected 9 billion gallons this year — more and more distillers grains have ended up in cattle feed (and, to a lesser extant, in hog and poultry feed).

    But like manure in a feedlot packed with corn-fed steers, problems associated with distillers grains as feed are piling up.

    A report from the Fort Collins-based Coloradoan sums up the situation.

    The article starts with a topic I’ve written about before: the link between E. coli 0157 and distillers grains, Turns out that distillers grains seem to make cows even more susceptible to E. coli 0157 than whole corn. As the USDA recently admitted, the distillers grains craze at least partially explains last year’s spike in meat recalls (though the agency has no plans of regulating distillers grains use).

  13. Beware the Myth of Grass-Fed Beef
    Cows raised at pasture are not immune to deadly E. coli bacteria.
    By James E. McWilliams
    Posted Friday, Jan. 22, 2010, at 7:24 AM ET

    On Monday, Huntington Meat Packing Inc. recalled a whopping 864,000 pounds of beef thought to contain a particularly nasty strain of E. coli bacteria called O157:H7. Coming shortly after the recall of 248,000 pounds of beef by National Steak and Poultry on Christmas Eve—and dozens of other scares over contaminated beef and pork—this latest news reminds consumers yet again that the mass production of meat can be very dangerous indeed.

    Consumers who still have an appetite for burgers and sirloins have been pushed toward alternative food sources. In particular, they’ve started to seek out more wholesome meat from animals raised in accordance with their natural inclinations and heritage. According to Patricia Whisnant, president of the American Grassfed Association, there’s been a dramatic rise in demand for cattle reared on a pasture diet instead of an industrial feed lot. Grass-fed beef should account for 10 percent of America’s beef consumption overall by 2016, she says—a more than threefold increase from 2006.

    The comparative health benefits of grass-fed beef are well documented. Scores of studies indicate that it’s higher in omega 3s and lower in saturated fat. But when it comes to E. coli O157:H7, the advantages of grass-fed beef are not so clear. In fact, exploring the connection between grass-fed beef and these dangerous bacteria offers a disturbing lesson in how culinary wisdom becomes foodie dogma and how foodie dogma can turn into a recipe for disaster.

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