Grassfed Beef vs Grainfed Beef - and why it should matter to you!

Reprinted with permission by Julius Ruechel,, all rights reserved.

The expression "you are what you eat" also matters to cattle. Although the difference between a grain-rich and a grass-rich diet has an enormous impact on the digestive processes that cattle use during digestion. And that difference doesn't just stop in the cattle's stomach. It affects their health. And it affects the kind of beef they produce. Which ultimately affects you!

Although beef from a grain-rich diet may look and taste nearly identical to grassfed beef produced on a diet rich in pasture grasses and legumes, the nutritional profiles of grainfed and grassfed beef are very different. And that in turn affects your health, because you are also what you eat...

Digesting Plants: the difference between grass and grain Grain and grass are both natural products, grown in a field. They are even part of the same plant.

We call it grass while the plant in its growing, immature stage. We call it grain once the plant reaches maturity and draws all the nutrients back out of the stalk and leaves in order to produce a seed head.

Even corn, wheat, oats, or barley are grasses if they are grazed before the plant sucks the nutrients out of the stalks and leaves in order to create the seeds.

However, while grass and grain can come from the very same plant, they are harvested (by the grazing cow or by humans) at very different stages of the plant’s maturity. This difference in plant maturity at harvest has an enormous impact on cattle digestion.

Digesting Grass

Cattle evolved to take advantage of grass. Their rumen (the first of their four stomach chambers) is filled with microbes and enzymes specifically designed to break down the tough cellulose structure of grass, allowing cattle to extract proteins and carbohydrates from grass.

You or I would starve to death if we tried to eat grass. Our stomachs were not designed to deal with cellulose. But a cow is a cellulose-busting machine, perfectly tuned to be able to turn grass into energy, fat, and meat.

Digesting Grain

Cows did not, however, evolve to live on grain. Grain requires a completely different set of enzymes for digestion and a completely different digestive process to unlock the nutrients contained inside the grain.

The grass-digesting microbes in the cow’s stomach are not able to crack the tough outer shell of grain and extract the nutrients from it. That requires a totally different set of microbes, which are only present in tiny proportions in the cow’s stomach and are largely inactive while the cow is on a diet low in grain.

Historically, when cattle only consumed a few seeds while grazing, the majority of these seeds would pass through the cow’s stomach largely undigested since the grain-processing microbes were so rare and largely inactive.

The grass seed, however, benefited from the journey through the cow’s digestive system because the seed hull was somewhat softened by floating around inside the cow’s juicy fermentation brew inside the rumen, making germination that much easier when the seed finally came out the other end of the cow. And, once that seed hit the ground and started to germinate, it was already surrounded by the perfect fertilizer mix, thereby dramatically increasing the seed’s growth potential.

It was a perfect mutually-beneficial relationship between cattle and grass - grass provided food for cattle in exchange for cattle helping plant the seeds for the next generation of grass.

What happens when the cow's rumen switches from grass to grain digestion

Remarkably, cattle are able to switch between the grass-digesting microbes and the grain-digesting microbes in their stomachs. But while either set of microbes can dominate the digestive process, they cannot both thrive simultaneously. Grass and grain cannot both be properly digested at the same time.

The switch from predominantly grass digestion to predominantly grain digestion happens automatically depending on whether grass or grain is the dominant part of the cow’s diet.

When grass is the main ingredient, the grass-fermentation process causes the cow’s stomach acidity to remain almost neutral at a pH of 6.4. But when grain becomes a large part of a cow’s diet, the grain-digesting microbes multiply substantially in the cow's stomach.