Ask A Farmer: Does feeding corn harm cattle?

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.

Do cattle eat grass or grain?

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.

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


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 bunk corn grains
Cattle feed bunks at the Winrock Stocker pens

The concentrates feed 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 this make the animal more efficient in obtaining energy for growth, reproduction, or weight gain.

Can eating grass make cattle sick?

Grazing cattle on forages in the pastures isn’t a cure-all, fix-all when it comes to 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 about a 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 armyworms, 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?

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. Similar to you sitting down and eating an entire box of corn flakes.


growing corn cattle food silage
Corn stalks in the field

In the stomach compartment of cattle called the rumen, there are microbes that digest foods into essential nutrients. The digestive system can utilize these 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. The animal is able to utilize that energy more efficiently on a diet that includes high-energy feeds like cereal grains.

cattle digestion forages corn
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. 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 notmakeupp 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 digestion grain corn
Cattle digest starches from grains into fatty acid building blocks

Learn more about what cattle eat

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 as 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. 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 there.

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

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.

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  1. Nice job Ryan, When ranchers spend six to eight months cutting and storing hay then two months feeding putting out hay day after day for hours. Everything I do is grass and hay. I’m on my way right now to check the growth of grass in the hay field. I forget we even feed corn.

    I shared my thoughts on grass finished beef with the post Grass fed beef- all hype or truly a super food ( )

  2. I was at a seminar not long ago and one of the speakers, a scientist, noted that grass eventually turns to seed (after all that is how it reproduces) and any cattle kept exclusively on grass must eventually eat that seed as the grass matures. So claiming pastured cattle do not get grain, is erroneous. His words, not mine. I like your statement to not hate your neighbor because he/she chooses differently. This is one of my soap box issues, the claim made by some producers that there is only one right way to do things. There isn’t, as you have so well stated. We are all in this together and we can support our way without putting down our neighbor who does things differently. Thanks, Ryan.

    1. There is one flaw in the statement of the scientist. Grass does eventually turn to seed. However, very few cows are on grass that is allowed to turn to seed. Forage pastures rarely are allowed to get mature enough to seed.

      1. I cannot speak from the animal nutrition side, but I can say that forages produced as hay are usually let go to seed at least partial fill. That is where much of the feed value and yield comes in. This includes oats, sudangrass, Rhodesgrass, bermudagrass and even corn to be ensiled. Most of the corn yield comes not from the stover, but from the ear.

        I note a prior comment questioning the “morality” of feeding corn to animals prior to slaughter. Maybe a better discussion for that person would be “does slaughtering cattle harm cattle”.

      2. Not true. There are actually a lot more operations that graze their cattle on grass that have headed out, and it happens WAY more frequently than you realize. Not all operations follow a rotational-grazing system that doesn’t allow grass to get to full inflorescence and reach maturity. Not every producer can rotational graze or move their cattle fast enough to beet the push grasses have to put their seeds out. We’ve grazed cattle on pastures that have headed out and cattle are still eating both the leaves and the heads.

        Native rangelands that are based on a transhumance grazing system have to allow native grasses like rough fescue to head out and reach complete dormancy before being grazed. It’s detrimental to rough fescue stands if they’re grazed like tame grasses (timothy, brome, tame fescues like tall and meadow, etc.) because they won’t have the same growth potential nor level of competitiveness if grazed after they’ve finished growing. Rough fescue is what we range nerds call “decreasers” in regards to grazing, meaning that grazing too often or even in a system of rotational grazing will push them out and eliminate their existence.

        And then we get into crop-residue and standing-crop grazing. Corn is fully headed out and mature when it is finally grazed standing. Crop-residue grazing has cattle cleaning up the grain spilled after harvest as well as the chaff left behind by the combine. Swath-grazing in the winter is done by using annual crops that have almost reached full maturity–meaning the heads have completely come out, but the seeds haven’t quite gotten to the hard-dough phase yet, and the crop is still green–which means cows are going to be eating seed heads along with the rest of the plant. Stockpile-grazing operates in the same way as transhumance grazing rough fescue that I mentioned above, and cattle on this type of grazing are, too, eating plants that have fully headed out.

  3. Excellent post. I will use it as reference information.

    I wonder why nobody ever seems to mention that corn IS a grass.

    And I wonder what form of corn non-farmers think the animals are fed–shelled corn? Ear corn? The entire stalk, including the ear? It sounds as if they think animals are fed shelled corn and nothing else.

    1. Hi Diana – my cows have no problem running through the best field of grass if they saw me standing on the other side with a bucked full of corn. This is how we move them from pasture to pasture, tease them with some corn because they cant resist it!

    2. Diana, cattle won’t eat just anything and finding the right mix of feeds for palatability is a concern when mixing cattle feed. They definitely find grains and their by-products palatable, sometimes even more-so than a pasture of forages.

      1. Thanks for responding, Ryan! I think most people who are conscientious about the health of their animals – pets or livestock – want to give them the most appropriate diet, which is why I’m curious what cows would naturally gravitate toward.

    3. It actually depends on how they were raised and what feeds they were exposed to as a calf. The dam can have a large influence on what a calf will gravitate towards because that calf will learn to eat what their mother will and that usually will stick with them for the rest of their lives.

      Your question, then, really depends on where they came from, what they have been taught to like when they were young (through teachings of their momma), how they were raised, and the palatability of the feed.

      For instance, cattle in the south that have been raised on corn and cows have gone nuts over the left over shells from shucking a corn head so that a producer can have corn-on-the-cob for supper with their family. Take another group of cattle that have never been introduced to corn or corn plants from birth, and if you give them that same corn, they won’t eat it because a) they don’t know what it is and b) they’re not too big a fan of trying something new, since cattle are always ever creatures of habit, and not open to novelty.

      But, of course cattle are always open to learning to like a certain feed if exposed to it enough. If a steer that has never seen, smelled or tasted corn in the grain and plant form, he will learn to eat it and like eating it if it is presented to him repeatedly for as long as it takes him to over come his caution and get his curiosity kicking into gear. But if he’s been used to grazing grass, eating hay and getting range pellets from when he was just a itty bitty calf because that’s what his momma always ate, then that’s what he’ll choose if given the choice.

      I’ve known this because of the training I had to do with each new group of steers we’d get every year to background. We’d have to teach them that eating cracked barley grain and silage was good, and we had to teach them not by showing them how to eat it, (because that would be just foolish) but by feeding it regularly to them so that they constantly get exposed to it. They may not eat it at first, or a few may get curious and try it out, but give it enough time and persistence and soon the entire herd will be eager to come and eat some grain and silage. Of course, they still had the choice to eat hay versus the new feeds given to them, so if they didn’t like it they were free to eat all the hay they wanted. This way we weren’t force-feeding them by forcing something on them and giving them no other choice of what to eat. Instead, we were just using the bovine curiosity complex to our advantage. 🙂

      1. wildrosebeef, thanks for the answer. I’m fascinated by how individual cows can be. This sounds a lot like how our guinea pigs are (another herd animal, though much, much smaller). Whenever we have brought a new guinea pig into our herd, there are vegetables he might not try until he’s seen them repeatedly and watched the other guinea pigs eat. Not eating things that are unfamiliar to you seems like a pretty smart survival strategy for most creatures.

        When you acquire new cattle, then, is it common practice to receive information about the cattle’s previous diet?

      2. For us, no. We could always tell what these animals were raised on by their behaviour. The calves that we got wouldn’t touch the barley and silage we set out for them to start eating on, but they’d go for the hay right away, or grass if we allowed them to graze. The cattle we got came via sales treaty between us and a local feedlot operator who would source our calves (purchasing through auction sales) and then we’d sell them to him when they were ready. The guy we got them from didn’t know what diet they were on prior to them being weaned and put on the truck, so neither did we.

        BUT, it’s different if we were to directly buy cattle right from a cow-calf producer for our backgrounding operation, you bet we’d know what their previous diet was! Then it definitely can be said that it would be common practice to get info on the animals’ diet prior to purchase.

  4. Reagardless, whatever they have changed about cows diet has changed the taste and smell of their meat. I definitely eat less meat because of these changes.

    1. Some of those changes may be in you. As we age our taste buds get old and die. It’s why older people salt their food to get it to taste better. I add some horseradish!

  5. Ryan, thanks for this info. It’s interesting that the corn question came up for you. I think that’s because, not necessarily all related to farming, corn is ubiquitous in American lives. Michael Pollan wrote an article about all the foods you can find corn in that I found on the link below when I was researching the uses for corn. It’s interesting, but he does critique farm usage a bit, so skip that part :). I just thought it was an amazing treatise on how much corn we humans consume in various shapes and forms:
    Thanks very much for the scientific breakdown on what you feed the cattle and why.

  6. Well written post Ryan. You did a good job of “digesting” down a complex subject and making it palatable to the technically unwashed.

    I guess the question from many of the adversaries of industrial ag is, does the high corn diet lead to or cause a higher population of E. coli? Many blame corn diets for the human sickness sometimes found by beef consumption.

    Would you please comment?



  7. I think the comparison to a high sugar, high fat diet for humans is instructive. We love it and it helps us get nice and fat. But it also kills many of us prematurely.

    “Both subacute and acute acidosis can lead to rumenitis (infection of the rumen wall). The low pH from acidosis creates lesions in the rumen wall. Damage to the rumen wall from sharp objects (such as wire or nails) predisposes the animal to abscess formation. When rumenitis develops, liver abscesses often follow. Bacteria (F. necrophorum, Actinomyces pyogenes, Bacteriodes spp.) from the rumen that cause liver abscesses enter the blood supply through ulcerative lesions, hairs, or foreign objects embedded in the rumen wall. These bacteria then travel via blood to the liver.

    Liver abscesses are most often seen in feedlot cattle. Severe liver abscesses may reduce feed intake, weight gain, feed efficiency, and carcass yield. Abscessed livers are condemned at harvest, regardless of abscess severity. Liver condemnations from abscesses were observed in 13.5 per cent of fed cattle in the 2005 National Beef Quality Audit, resulting in about a 2 per cent reduction in carcass weight per head. Abscesses were the primary cause of liver condemnations”

    This is clearly not the diet you would choose for cattle if you were trying to get them to live a healthy long life. This is a diet to fatten them up quick for slaughter and to give the meat a particular taste. Whether this is right or wrong depends on your individual morality.

    1. Thanks for the comment Dave, and I am aware of this. We need to manage our feeding strategies better to avoid acute acidosis in finishing cattle. Keep in mind, just because it happens, doesn’t mean it happens all of the time.

    2. Very nice point Dave with some good data.

      It struck me that in the section on “does eating grass make a cow sick” he went over all sorts of plant “toxins” and made grass sound really dangerous (even though that was 90% of their diet since cows evolved). And then in the next section “does feeding corn to a cow make them sick” he just says, “oh, maybe an upset stomach.” Clear bias here and a complete gloss over the real dangers to the cows and to us eating corn-fed beef for life.

      The fact is cows never ate corn (or any grain) in any substantial portion before we had so much after WWII that we began feeding it to them in droves. The fact that they “love” it, as is claimed, is because it is sweet and starchy — in evolutionary terms, it can make them fat and help them survive. Only cows don’t know that. Just because they love it doesn’t say anything about if it nourishes them or us for the long term.

      This article completely glosses over the dangers of feeding cows so much corn. It’s destroying the cow’s health (about 1 in 5 have absessed livers, as pointed out above) creating more need for antibiotics, creating more greenhouse gasses, destroying the top soil (albeit, in an indirect way) and destroying our health by disrupting the important fatty acid profiles in the meat and through residual hormones and antibiotics. My question is: what’s happening to the other four cows? Probably a lot that, because of their short lives, is not coming to fruition.

      But corn isn’t the only problem — they’re also fed soybeans, candy, chicken feces, feathers, the leftovers from the production of canola oil, and pretty much whatever other industrial by-products can legally be shoved in their mouths.

      If you care about your own health, your heart, or not getting cancer, or the health of the soil and air, you would be wise to stick with grass-fed/finished traditionally raised beef.

      1. That’s not necessarily true. Here in Kentucky, cattle have been eating corn since as early as the 1800’s. They were most often wintered on corn and then supplemented on corn along with spring gasses until the cattle drive to the markets. And we’re a forage state.

      2. The “no hormones, no antibiotics” labelling on “natural” raised beef is a misnomer. Cattle still produce hormones naturally, and the level of hormone “residue” in the meat is tiny compared to the level of hormones found other sources like soybeans and the like. The level of hormone found in an implanted animal versus a non-implanted one is slightly higher, like only 0.3 nanograms.

        Antibiotic residue issue is also misinformation, because drug and antibiotic labels clearly state the withdrawal time from the time an animal is injected to the time it can go for slaughter. Feedlots use health records and make due note of withdrawal times for the antibiotics they use, and act accordingly.

        You bring up another pet-peeve of mine: the opposition of using by-products. What else are we supposed to do with these by-products if we aren’t supposed to feed them to livestock? Dump them in landfills? Ryan did mention how cattle are better equipped to digesting certain feedstuffs that we simply turn our noses up at or would rather throw away than use for our own benefit. These by-products aren’t as much of a “problem” in the livestock industry as the attitude by people like you who don’t really understand the whole picture. These by-products aren’t being “shoved in their mouths” per se, it is only used in small quantities and incorporated into the feed to increase nutrient value of the feed they’re fed. And this isn’t pertaining to just beefers in the feedlot, dairy cows make good use of these feeds too.

  8. I think Dave has come closer to the most important point than anyone else. However the technical issues involved and even the moral ones are moot beside the biological one. We’ve changed what we eat and how we eat more in the last century than in the last 10,00 years and it’s clearly killing us. It’s time to back up the bus while we still can and examine the food chain from start to finish.

  9. Reblogged this on Farmers 4 Choice and commented:
    Corn is grown to feed people, put fuel in your cars and make thousands of product’s both edible and non edible like plastics. Our desire for corn is not solely fast food…Cattle are able to digest corn but corn like other rich concentrates to their diet can give them an upset stomach; hence the feed silage that is made with corn and other legumes to provide a supplement to their grass feed when needed. See the link below for the true facts on Cows and Corn…Ryan has a comments section if you care to challenge your perceptions.

    1. What about the quality of meat in grass fed (omega 3 and other good fats) vs grain fed ? When I see grain fed meat in the grocery stores I’m thinking nasty CAFOS. When I think grain fed I think grain from a feed store not corn stalks in a field. Of course the cows run for the grains when it’s mixed with sorghum. Lol That’s like sweets for kid’s.

      1. Thank you for educating me. I thought all cattle was strictly grass fed up until the mid 70s.
        I thought the FDA made a decision to go almost all “Feed Lots” to feed the masses like they did on corn.
        Why do they sell “Grass Fed” beef in the select stores? Most people do not like the taste.
        Ken Tubman _ Napa, CA

      2. First. Ryan, thanks for writing such a straight forward article. To those that object: bias is inherent to ones perspective. When discussing or replying to any issue keeping this in mind may help you to remember that you too have a unique perspective. If an article such as this gains your attention and is without rhetoric or hype, would you not then wish to join the discussion and share your perspective?
        To Ken in Napa: First, I don’t know that the FDA would have any involvement. Maybe the USDA? I found this reference on Google Books: ‘Cattle feeding with sugar beets, sugar, molasses, and sugar beet residuum’ By Lewis Sharpe Ware. Published in 1902 the preface discusses (and promotes) farming beets in this country specifically as a cattle feed and states that much of the authors research supporting this practice was conducted utilizing USDA publications and also, 1st hand studying similar, well established practices in Europe. [googlemaps
        As for grass fed vs. grain finished beef: Tastes are individual. To say the least! And what you’re used to eating influences this. Grass fed beef does taste different. Not bad. I encourage you to sample beef from a variety of producers within your region. I know from personal experience that 2 animals from the same origin ranch can taste different when finished only 30 miles apart. Think micro climates!

  10. Stopped reading when they compared cows eating 100% corn diet to me eating a box of corn flakes. Fix that and I’ll humour you once more

  11. On my grass-fed dairy our cows live to be 14 yrs old on average; in a corn-fed dairy its less than 5 years on average… My milk sells for $6.50 gallon with a cost of about $.75 per cow per day. I make more than the commercial and I spend less doing it. I’m not hating corn feeding I’m just asking why…because that’s what the government university told you to do? Grass-fed beef also sells more than grain-fed and cost so much less to produce. If it keeps the animals alive longer and is more economical why not just pasture raise the cow? Alfalfa and hay store just as well as corn. I’d love to get a discussion going about GMO corn being fed to cows…that’s would be a big can of worms on this site. Thanks for allowing opposing views! I’d love to win you over to the grass side:) To those of you who say corn is a grass…how is it that farmers can spray grass killer on a field of corn and the corn lives but the grasses die? Why is the corn you eat and is feed to the cows you eat considered an herbicide? Food for thought…

    1. Alex, based on your financials it sounds like you do what is best to line your pocket not necessarily the best animal husbandry. You are the only comect to brag on your bottom line.

  12. Hi, I live in GA and am considering raising cattle and want to know how much does a cow eat per day. I have foundfoundthe mathimatical equations and percentages but cant seem to wrap my head around it. Is there anyway I can figure out what and how much by the pound they eat. I plan on letting them feed on Blue Grass pasture, soybean meal, oats, corn, and possibly alfalfa hay.

    Thank you!


  14. Interesting discussion. The bottom line is grass fed beef is lower in saturated and mono-unsaturated fat, mucher much higher in omega-3 fatty acids, and higher in Vitamen A, E and micronutrients. It’s just healthier, for the same reason venison is healthier. If you eat a lot of beef it’s then a greater concern and you should consider paying extra for grass fed beef, for someone who only occassionally eats beef it’s not a big concern.

      1. Not true, grass-fed is 15-20% leaner than grain-fed on the low end. Which is why it is so much tougher to get it to grade highly. Don’t get me wrong, I like grain-supplemented beef. It’s plenty healthy for steaks and other things that aren’t cooked for very long. But I do have to respectfully question some of what you wrote in the article. You said that if you feed a cow nothing but grain it will get a stomach ache. My understanding is that (and I’m talking large scale feedlot operations here) after 6 months or so on grass and milk they go to backgrounding pens to condition into exclusively grain diets. And they do get “stomach aches”. AKA bloat and acidocis and, ultimately, liver abscess. My friends who run smaller operations use fermentation to battle this, which seems pretty effective. But to say that a cow can just eat plain or dried corn seems like a half truth. Am I wrong about this?

    1. My first question would be what are your objectives for feeding these cattle? Looking to supplement energy if they are not getting enough from forages? Or are you looking to add energy to the diet for finishing?

      Once you’ve answered those, yes, I would suggest that corn is a great ingredient for increasing energy in the diet when needed.

  15. We have a black angus bull calf that we want to butcher at about 800 lbs. and would imagine he would be about a year old by that weight. I wondered how we should feed him differently, and if so at what age. He is with other cattle in nice Coastal Bermuda pastures with supplement tubs year round, and in winter we supplement with CB hay. have always sold our calves so not sure exactly what is best for this purpose.

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