Cows do not eat chicken or any other kind of meat. As herbivores, their natural diet consists strictly of plant matter, such as grass, hay, and grains. Confusion about this topic stems from a historical, non-natural practice in the livestock industry that attempted to alter the diets of these grazing animals. This practice led to a major health crisis, resulting in strict, permanent regulations that ensure cattle remain true to their herbivorous nature today.
The Ruminant Digestive System
The biological design of a cow makes its digestive system unsuitable for consuming and processing meat proteins. Cows are classified as ruminants, mammals characterized by a complex, multi-chambered stomach system evolved to break down tough plant fibers like cellulose. Their digestive tract consists of four distinct compartments: the rumen, reticulum, omasum, and abomasum.
The first and largest compartment is the rumen, which acts as a massive fermentation vat, holding up to 40 gallons of material in a mature cow. This environment hosts a dense, symbiotic population of microbes, including bacteria and protozoa, which produce the enzyme cellulase. Since a cow cannot produce this enzyme itself, it relies entirely on these microorganisms to break down the cellulose in grasses and hay.
The fermentation process in the rumen converts plant carbohydrates into volatile fatty acids, which the cow then absorbs for energy. The abomasum, the fourth compartment, is often called the “true stomach” because it functions similarly to the single stomach of non-ruminant animals. It secretes hydrochloric acid and digestive enzymes designed to break down the proteins of microorganisms, not to efficiently process complex animal tissue.
Historical Use of Animal Proteins in Cattle Feed
The question of whether cows eat meat is rooted in a past industry practice where animal proteins were used as a low-cost feed supplement. This was primarily achieved through Meat and Bone Meal (MBM), a product created by the rendering industry from slaughtered animal byproducts, which historically included various livestock remains, including poultry. MBM was added to cattle feed to boost protein and fat content, aiming to accelerate growth and improve feed efficiency.
The practice became widely adopted, particularly in the mid-20th century, as a way to recycle materials and provide a dense nutrient source that was cheaper than traditional vegetable proteins. This system, however, inadvertently created a pathway for a devastating disease to spread. Bovine Spongiform Encephalopathy (BSE), commonly known as Mad Cow Disease, is a fatal neurodegenerative disorder caused by a misfolded protein called a prion.
The prion disease spread rapidly when MBM derived from infected cattle tissue was rendered and then fed back to other cattle. This act of recycling infectious material within the same species allowed the prion to amplify quickly in the cattle population. The BSE crisis, commonly known as Mad Cow Disease, peaked in the United Kingdom in the 1980s and 1990s and was directly linked to these feeding practices.
Current Feeding Regulations and Safety Measures
Following the devastating effects of the BSE outbreak, regulatory bodies worldwide implemented strict feed bans to permanently prevent the use of certain animal proteins in ruminant feed. In the United States, the Food and Drug Administration (FDA) established the regulation 21 CFR 589.2000, which prohibits feeding most protein derived from mammalian tissues to cattle and other ruminants. The regulation specifically targets materials that could transmit the infectious prion.
This rule means that cattle feed cannot contain proteins from sources such as rendered material from other cows, sheep, or goats. The ban necessitated significant changes in the feed industry, including strict procedures to prevent the cross-contamination of ruminant feed with feed intended for other animals like pigs or chickens, which may still contain non-ruminant MBM. Feed manufacturers and distributors must maintain detailed records and label all feeds containing prohibited material with the cautionary statement, “Do Not Feed To Cattle Or Other Ruminants.”
While proteins from non-mammalian animals, such as poultry by-product meal or fish meal, are generally not included in the strictest bans, their use in ruminant feed remains rare and subject to stringent control measures. The regulatory framework ensures that the dietary intake of cattle is carefully managed, guaranteeing the animals consume a strictly herbivorous diet.