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A possible cause for the lack of microbial diversity in the US is the quality of the pasture grass ingested by cows and other livestock compared to that of traditional pastures found only in parts of the US and most of Europe. The theory I will investigate in this newsletter focuses on the increased microbial diversity that has been documented in the intestinal tracts of Europeans and it’s connectivity to Europe’s nutrient-rich grasses and high-probiotic diet of dairy products.
As it turns out, animal grazing is essential for healthy pastures and has been keeping the insects, birds, mammals and the pastures themselves healthy since the last Ice Age. Pastures either left alone or overgrazed become more fragile. Too much or too little grazing puts the field at risk for undesirable invasive species. (1) Interestingly, these invasive species were found to be less tolerant to drought and environmental disturbances. (1)
I’ll be in Europe for the next three weeks conducting a microbiome trial and investigating some of the practices common in Europe that may be contributing to a greater diversity and richness of microbes in the European population.
The Term “Grass-Fed” Is Open to Interpretation
A healthy pasture is rich in many types of grasses and vegetation. Micrograsses and clovers act as ground cover, meadow fescue grows closer to the ground, while tall grass fescue, rye grasses and other types of orchard and pasture grasses reach a variety of heights. Austria’s Vorarlberg and Tyrol regions boast that their pastures have over 50 species of pasture grasses and herbs.
These are the pastures of old, the kind we don’t often find stateside.
In fact, in the Colorado grass-fed cow pastures I reported on in the video associated with this article, it is clear that there is but one type of grass the cows graze on.
Intuitively, we may know that botanical diversity in a pasture equates to a greater, more resplendent array of nutrients and beneficial microorganisms in that pasture. But this trend is also well-documented through a plethora of recent research, which cautions us against mono-cropping and other practices that curtail botanical diversity.
So, when we see that cows raised on a richly diverse field in Austria and cows raised on a single grass type in the United States are all lumped together under the umbrella of “grass-fed,” we might ask, how we can compare the two, from the perspective of nutrient density and microbial diversity?
Grazing and the Cyclical Microbe Exchange
Each species of grass carries with it a diverse palate of nutrients for the grazer and, maybe more importantly, a unique food supply for the multitude of microbes inhabiting the belly of the grazer.
The variety of microbes ingested by the grazers get passed along as feed for their young via the mothers’ breast milk and, in the case of cows and some other grazers, as dairy for human consumption, (for those so inclined).
Note: Eating dairy is by no means a requirement for optimal health. There are many other ways to get the diversity of microbes we need for optimal health.
As the grazers eliminate waste and the numerous grass species decompose, a pre-biotic explosion of nutrients hits the soil, feeding the microbes in the soil that are attracted to specific plants that are then in turn eaten either by humans or grazers. Quite a unique and beautiful sliver of the circle of life!
Dangers of Over-grazing
Balanced grazing supports the entire ecosystem of the grasslands, and necessarily involves moving the grazing creatures to new pastures before all the grass and ground cover of the current pasture gets eaten. This requires having enough land to successfully rotate the grazers, which for some ranchers poses a problem, running out of new pastures before the already grazed pastures have had a chance to recover and flourish.
An over-grazed pasture will be left extremely vulnerable to drying out and being overrun by invasive species. In short order, the stronger grasses survive and the more delicate grasses, clovers and ground cover that support nutrient and microbial diversity vanish, rendering the pasture significantly less diverse, often a mono-grass pasture at this point.
With over-grazing, diversity of insects, butterflies, bees, birds, vertebrates, grasses and plants, and consequently the all-important microbial richness and diversity disappear.
Cows that feed on these scrub grasses are still called “grass-fed,” while getting significantly fewer nutrients and microbes in their diet than they would from a healthy and balanced pasture.
Luckily, these consciously cultivated and preserved balanced pastures still exist in Europe, and in certain more conscious areas of the US.
In Europe, cows are taken up to the high mountain pastures during the summer and are free to roam, never being confined to overgraze a single area, thereby preserving the diverse botanical and microbial species.
In his book, The Omnivores Dilemma, Michael Pollan makes the case for Management Intensive Grazing (MIG), which uses modern techniques that mimic traditional European grazing practices. Joel Salatin sets an example on his Polyface Farm in Virginia’s Shenandoah Valley, moving his cattle frequently before they have a chance to graze into the lower grasses and ground cover. This means that Joel’s cows are constantly exposed to not only a variety of grasses and their respective microbes within a given field, but are given a greater space in which to likely stumble upon some unexpected microbial and nutrient diversity. Given a little space themselves, the grasses actually recover faster and stronger as a result of grazing.
Please watch this TED talk describing research showing that it is the lack of properly managed grazing (mimicking natural herd migration) that is causing the rapid desertification of the majority of earth’s surface and is a major contributor to global warming.
Critics make a good case that pastured beef is unsustainable because it takes too much land (an estimated 10% of US land) to feed the entire US with grass-fed beef. As it turns out, it typically takes 2.5 acres per cow to raise pastured cows in the standard way, but using MIG techniques can cut this down to 1.2 acres per cow (as demonstrated by Joel Salatin and his healthy pastured cows). Dairy farms using MIG will also of course be able to feed a much larger population in a more sustainable fashion.
In a parallel vein, we can make the case that mass produced organic vegetable farms that process their vegetables on conveyor belt platforms and sell them triple-washed will carry a more limited microbial diversity compared to veggies grown on the ground mingling with a variety of other vegetable species in soil that is rich in naturally decomposed plant matter.
More and more small farms are popping up that allow us to see up close the pastures and practices of the farmers before we buy – a fact worth celebrating! Spending the time to locally seek out and support such farms may be the fastest way for the US to regain the microbial diversity we have lost.
In the videos associated with this article, I show the difference between a typical grass-fed cow pasture in Colorado and a typical European pasture.
Labels to Look For Now and In the Future
To qualify for the USDA grass-fed label, cattle must be fed only mother’s milk and forage (grass and other greens) during their lifetime. The forage can be grazed or consumed as hay or other stored forage. Also, the cattle must have access to pasture “during the growing season.” (2)
The American Grassfed Association (AGA), an organization of pasture-based ranchers, consumer groups and researchers, is creating an alternative label. To qualify for the stricter AGA label, cattle cannot be confined during their lifetime, nor treated with hormones or antibiotics. The American Grassfed Association maintains that this is closer to the public’s perception of “grass-fed.” (2)