The first thing to understand about a cow is that her stomach—called a rumen—is not meant to be acidic. Unlike the human stomach that uses acid to digest food, a cow relies on rumen bacteria. (By the way, a cow has four stomachs, but the rumen is her main stomach). When a cow is fed large amounts of rapidly digestible carbohydrates—such as corn or other grains—the rumen pH changes from alkaline to acidic. These changes to the rumen flora allow acid-producing and acid-loving bacteria to take over. E.coli 0157:H7 is one such bacterium. And distiller grains, an ethanol by-product, have been shown to further increase the presence of E.coli in the cow's hindgut even more than regular corn.
When acid-loving bacteria takes over the cow's rumen, the cow's manure will also contain the same bacteria. Where other bacteria would be killed in the acidic environment of our stomachs, this acid loving E.coli can pass straight through the human gut and go on to cause kidney failure, heart attack, brain damage, and much more. (See Part 1 of The Whole Cow). This is one big reason why it's not a good idea to feed cows corn instead of grass.
Nonetheless, it's important to point out that even the rumen of a grass-fed cow can become acidic (known as acidosis) and subsequently harbor E.coli 0157:H7 and other dangerous strains. It happens when cows eat too much short, lush grass which is a rapidly digestible carbohydrate. Longer grass, with its fiber, is needed to balance the cow's diet and its rumen.
The grass farmer who rotates his cows from pasture to pasture at longer intervals—allowing the grass to get long (18 -24 inches tall)—can greatly increase the health of his cows and therefore the food he produces. Add organic methods to the carefully managed pasture rotation and the risk of disease decreases even more. Conversely, the corn-fed, non-organic cattle add to the threat of not only producing E.coli, but also increases the chance that the bug will be antibiotic-resistant since it lived in the presence of low-doses of antibiotics.
Let me sum it up.
- Heavy grain feeding produces pathogenic E.coli in the gut of a cow
- Feeding distillers grain (ethanol by-product) further increases pathogenic E.coli in the cow's gut
- Grass-feeding reduces pathogenic E.coli in a cow's gut
- Organic, grass feeding further reduces how dangerous the pathogens are (less antibiotic resistance)
- Organic grass feeding with careful pasture rotation to provide sufficient fiber is the best known way to reduce pathogenic E.coli in the gut of a cow
- Last, but not least, a good testing protocol aids in verifying that the sanitation and hygiene procedures are effective.
Remember, raising truly healthy food is like climbing a ladder: each rung is essential to reach the top. And when it comes to cattle, the ladder begins with grass. Increased health in cows means decreased risk of dangerous strains of E.coli. And with fewer pathogens in the manure, there are fewer pathogens in the farm environment. Less pathogens in the farm environment means less chance of these pathogens subsequently finding their way into the food supply.
In this case, less is clearly better.