What is a Factory Farm? Does feeding cattle corn harm them? Why are cattle finished in feedlots? These are a few of the questions I often receive when discussing the beef we eat and how cattle are raised. During the next few posts we will address a few of these concerns.

Do cattle eat grass or grain?

Cows grazing high-quality pasture is a common practice on cow-calf farms

Most all beef cattle are born and raised on pastures where their diet consists primarily of grasses, legumes, and other forages. These feeds are high in fiber and lower in digestibility of nutrients. The stomach of cattle is made of different compartments and is able to digest these fibrous materials. When cattle on pasture need more energy than can be obtained from forages, the farmers may feed them supplemental feeds that come from a number or sources, including concentrates that will be explained below.

Do farmers feed cattle corn?

After cattle are weaned (approximately 7-8 months of age, shortly before puberty), most continue to receive forages as a large portion of their diet. This is important to help their stomach continue to grow and develop properly. However, forages do not provide the high amount of digestible energy these cattle need to grow quickly. Farmers are able to utilize a number of feeds that are higher in digestible energy and lower in fiber – we refer to these as concentrates.

Cattle feed bunks at the Winrock Stocker pens

The concentrates feeds can include cereal grains (corn, wheat, oats, barley, sorghum), the by-products of milling or processing these grains (soybean meal, cottonseed meal. peanut meal), or by-products of ethanol or alcohol production (distillers grains). These feeds are more efficient sources of energy for the stomach in cattle, in turn making the animal more efficient in obtaining energy for growth, reproduction, or weight gain.

Can eating grass make cattle sick?

Mike Haley’s cows are choosing to eat corn on the edge of the field

Grazing cattle on forages in the pastures isn’t a cure-all, fix-all when it comes to cattle health. My friend Jesse Bussard just finished her studies at the University of Kentucky studying fescue grazing in cattle. She has written on many topics where forages can threaten cattle health. Some plants are poisonous to cattle, others contain toxic endophytes or chemicals called gossypol that can be detrimental to cattle health. There are concerns for mineral imbalance that causes grass tetany or even bloat when forages are lush and green. Grazing pastures are more dependent on rainfall in periods of drought (compared to stored feeds). This year we’ve seen many instances of toxicity in plants due to nitrates that build up in the plant during drought, and surge into the plant when moisture arrives, causing toxicity problems in cattle (prussic acid), even though these are natural compounds. During any growing season we also have concerns of pests, like army worms, that can wipe out entire pastures. When these conditions occur, despite great management by farmers, it is important to have other feeds, like grains, available to feed cattle.

Does feeding corn harm or kill cattle?

Corn stalks in the field

This is a claim I hear by many folks. Feeding cattle corn or other cereal grains, or their by-products does not kill the animal. Feeding these grains as 100% of the diet will give the animal an upset stomach, just like if you sat down and ate an entire box of corn flakes.

In the stomach compartment of cattle called the rumen, there are microbes that digest foods into essential nutrients that the digestive system can utilize as building blocks for body requirements. Forages and concentrates contain a source of energy in the form of two different sugars - cellulose in forages and starch in concentrates.

How do cattle digest grains like corn?

The microbes in the rumen of a cow eating only forages are adapted to digesting primarily cellulose. IF this animal were to ingest a large amount of starch containing feeds (much like you eating a large amount of candy on Halloween) it would be a shock to the system. However, the microbes in the stomach have the ability to shift and adapt to digesting starch as a portion of the diet. Given an adjustment period – switching the animal’s diet from primarily forages to concentrates – the microbe population adjusts and the animal is able to utilize that energy more efficiently on a diet that includes high-energy feeds like cereal grains.

Cattle digest cellulose from forages into fatty acids for building blocks

When this switch in diet is done rapidly, the pH (acid) of the rumen is disrupted, causing a condition called acidosis. This may be what many people refer to when claiming that feeding cattle corn makes them sick. This is something that cattle farmers try to avoid, but when it does occur, acidosis can be corrected by adding more forage to the diet and paying close attention to the transition in diet. Corn does not make up 100% of the diet. The diet of cattle is usually a mixture of many feeds, mixed in the correct proportions to give the animal what it needs for its stage of growth or production.

Cattle digest starches from grains into fatty acid building blocks

So to wrap it all up, yes cattle do eat corn, many other cereal grains. They love these feeds [video]. Don’t believe me? They will run you over for it. These feeds are good for them because they are a great source of digestible energy for cattle growth, reproduction, weight gain, and any other metabolic processes.

For the record, I love beef from both grass- and grain-finished cattle. Each has its unique qualities in production and taste and I am so grateful for the opportunity of choice between the two. Choose what fits best for you, but don’t hate your neighbor because he/she chooses differently. In the next blog post, I will address the topic of feeding cattle in feedlots (some refer to these as factory farms or confined animal feeding operations) using my experience working in them.

If you have more questions about what cattle eat, I encourage you to visit these blogs by farmers from across the country that I trust and look to for information, insight, and experience.

• Ray-Lin Dairy, California – What Do Cows Eat?
• Dairy Carrie, Wisconsin – So What Do Cows Eat Anyways?
• Kathy Swift, DVM, Florida – What Do Cows Eat and Why? (feat. on janiceperson.com)
• Haley Farms, Ohio – But Your Cows Do Eat Grass?
• Jeff Fowle, California – It’s More Than Corn (Series)
• Zweber Farms (Organic Dairy), Minnesota – Making Winter Feed for Our Cows

Submit your own questions via the Ask A Farmer tab on this blog!

What other questions do you have about what cows eat? Leave your comments below and I’ll include them in a later post.

Related articles

• Farmers aren’t evil. Now can we have a civil conversation? (eatocracy.cnn.com)
• Ask A Farmer: Questions about food and farming abound (agricultureproud.com)