Food Industry & Politics

3 BIG Reasons Why Cows Shouldn’t Eat Corn

When it comes to animal agriculture, feeding practices matter.  Cows are herbivores who by nature have evolved to eat grass.  However, in a way to provide cheap feed that will fatten them up quicker, cows raised on industrial farms are forced to eat corn.  In spite of all the evidence showing the devastating effects of this feeding practice, many consumers still believe that this is a harmless practice. We have been programmed to believe that government organizations implement tight regulations that keep anything that might be harmful to our health off the supermarket shelves.  This couldn’t be further from the truth.  The fact that we’ve eaten trans fat for decades before its ban from human foods by the FDA indicates serious flaws in the system.  But let’s get back to cows and corn.

Years ago the majority of cattle farms were converted to what are now known as concentrated animal feeding operations (CAFOs).  They are hideous operations that cram as many cows as possible into one space (hundreds of cows) where the cows stand, for the most part, in the same spot their entire adult life and do nothing but eat feed that primarily consists of corn.

Concentrated animal feeding operations were the industry’s genius way to increase production by fattening up the cattle quicker while fitting many more animals into less space.  Of course, nobody ever thought about what forcing a cow to eat corn would do to the environment, the animal’s health, or the health of the people who eat the meat from these cows.  Yet these are exactly the three BIG reasons that cows should not eat corn:

  1. It destroys the environment and natural ecosystems at alarming rates.
  2. It creates disease and bacteria inside the animal that would not otherwise be present.
  3. It distorts the fatty acid profile and nutritional value of the finished meat by creating unhealthy ratios of polyunsaturated fats and eliminating the diverse antioxidant content naturally found in beef from grass-fed cows.

Environmental Destruction

Corn used to feed cows in CAFOs is genetically modified (GMO) corn.  This means the seeds to grow this corn were genetically modified so that the corn itself becomes a pesticide.  It resists bugs and pests that can potentially destroy the crop.  However, you can drench it in as much herbicide as you’d like to kill competing weeds because it’s herbicide resistant and can sustain all the Roundup® you want to give it.  Also, it thrives on nitrogen-based fertilizer, which is liberally spread among GMO corn crops each year to maximize the farmer’s yield.  This practice alone, drenching approximately 85 million acres of GMO corn in the United States with nitrogen-based fertilizer, is just one reason GMO crops are so devastating to the environment.

These nitrogen-based fertilizers used to grow the GMO corn that feeds cattle and other industrial farmed animals is responsible for the increasing size of “dead zones” that form each year in the Gulf of Mexico, Chesapeake Bay, and other areas worldwide.1  Although weather incidents such as floods and hurricanes may contribute to the growth of dead zones, the primary cause is from the run-off of nitrogen and other waste products from industrial farms.  Because nitrogen, phosphorous, and other components of this waste are technically nutrients, this process is sometimes referred to as “nutrient pollution.”  In this case, excessive manmade levels of these nutrients create a toxic environment for the marine life.

This nitrogen overtakes the oxygen content of the water promoting a tremendous overgrowth of algae and other bacteria that eventually depletes the oxygen content of the water further to create a dead zone where the marine life suffocate and die, or leave if they are able to swim out of the zone.1  While coastal dead zones are, to an extent, a natural occurring event, industrial farming is increasing the size of these dead zones by disturbing proportions, making industrial animal agriculture a top contributor to this concerning environmental issue.  Furthermore, these farming practices destroy the topsoil and surrounding ecological systems that are crucial to sustain the natural life-cycles of existing insects and animal species that all other species – including humans – depend on to survive.

Approximately 60% of the GMO corn grown in the United States is used to feed industrial farmed animals with the majority of it being eaten up by cattle.2  Raising cows on grassland under sustainable farming systems would greatly improve environmental conditions.  And I haven’t even mentioned the environmental problems created by the enormous ponds and rivers of cow pee and poop that build up around the CAFOs.   Buildup of their waste in one concentrated area also contributes to environmental destruction, which again is avoided on sustainable animal farms.  On sustainable farms that practice intensive grazing, animal waste is recycled back into the natural flow of the life-cycle of the land and animals.  This serves to regenerate the land rather than destroy it like GMO crops.

Disease and Bacteria

Another serious issue created by feeding cows corn is the fact that it lowers the pH in their rumen (the cow’s version of a stomach).  Under normal feeding conditions where a cow is allowed to eat its natural diet composed of various grass species and weeds, many bacteria live in a pH environment much higher than that found inside a human’s stomach because a cow’s rumen is less acidic than the human stomach.  This means that most bacteria, including Escherichia coli (E. coli) that live in a cow’s stomach, are strains that originate in a place with a lower acid content.  By lowering the pH inside the rumen, and thereby increasing the acid in the rumen, potential mutations in E. coli strains may occur that allow the new bacteria to survive in more acidic environments such as a human stomach.

Although a search on the internet will result in conflicting information, it is largely accepted by many that the mutation creating the harmful and potentially deadly O157:H7 E. coli strain was a result of feeding cattle corn.2  Furthermore, changing the pH of the cow’s stomach increases the animal’s own risk of contracting disease making the use of antibiotics necessary to prevent the potential spread of disease among the overcrowded CAFOs.  Of course, antibiotics won’t kill all the possible pathogens that can contaminate your meat.  To solve this problem the meat is irradiated or subject to some type of chemical processing to kill all these harmful bacteria.  The end result:  you get to eat meat full of antibiotics and depleted of many essential nutrients.  From a health standpoint, that’s exactly what we don’t want.

Fatty Acids and Nutritional Profile of the Meat

While the debate about whether red meat truly causes cardiovascular disease or not is bound to continue for quite some time, most nutrition professionals agree about one thing.  Meat from grass-fed cows has a much better nutrition profile than the meat from cows that eat corn.  One of the most important differences between the two is that grass-fed meat contains much higher amounts of omega-3 fatty acids along with lower amounts of omega-6 fatty acids3, so it can serve to correct the outrageously skewed ratio of omega-6 to omega-3 fats found in the Standard American Diet (SAD).

Furthermore, it contains many antioxidants and higher amounts of minerals than corn-fed meat.  Irradiation or chemical cleaning isn’t necessary when producing grass-fed beef, and more than likely you’re getting a better quality of protein from grass-fed meat since this is the natural diet that the animal is, by nature, designed to eat.


  1. Scheer R, Moss D. EarthTalk®, Scientific America.  Accessed March 31, 2018.
  2. Pollan M. The Omnivore’s Dilemma:  A Natural History of Four Meals. [Kindle]. New York, NY:  Penguin Group (USA) Inc.; 2006.
  3. Daley CA, Abbott A, Doyle PS, Nader GA, Larson S. A review of fatty acid profiles and antioxidant content in grass-fed and grain-fed beefNutrition Journal. 2010;9:10. doi:10.1186/1475-2891-9-10.

About Laura Cadoret, MS

Helping people see the big picture in food industry and nutrition
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