Cows are amazing creatures. They have the ability to convert foods that we, as humans, would not be able to utilize, into a food that we can consume.
Cows can utilize material that contains cellulose. Cellulose is present in plants, and gives plants strength, allowing them to stand and grow upwards (instead of flopping over). While humans can consume cellulose, we don’t have the enzymes to break the material down to be able to utilize the nutrients contained within it. In contrast, cows can convert cellulose to energy. They have protozoa and bacteria in their digestive systems that can break the cellulose down into shorter carbohydrate chains, and eventually glucose.
In addition, there are waste products available from different industries. For example, tomatoes are made into ketchup, sauce, soup and juice. The skin, seeds & fiber left over are collectively called tomato pomace.
Another example is from the cotton industry. The cotton is taken off the seed and utilized for clothing. However, the cottonseed remains. By-products (like tomato pomace and cottonseed) can be fed to dairy cows. The cows can utilize the by-products, as they have protozoa and bacteria to break down the material, and convert it into nutrients to fuel their bodies. More examples of products humans use and the by-products that cows can use are listed in the table below.
| Product Humans Use | By-Product that Cows can Use |
| Almonds | Almond Hulls |
| Beer/ Malt (Corn, Barley) | Brewer’s Grain |
| Cheese | Whey (liquid or dry) |
| Corn Meal | Hominy |
| Corn Starch | Corn Gluten Meal |
| Cotton for clothing | Cottonseeds (whole or meal) |
| Ethanol (Corn) | Distillers Grain |
| Fish | Fish Meal |
| High Fructose Corn Syrup (Corn) | Corn Gluten Feed |
| Peanuts | Peanut skins |
| Soybean oil | Soy hulls |
| Sugar Beets, Sugar Cane | Molasses |
| Tomato for sauce & juice | Tomato Pomace |
| Wheat flour | Wheat Bran |
The coolest part is that cows can then use those nutrients to make foods that we can consume and get nutrition from – milk and meat. As such, these gentle giants are one of nature’s recyclers. Think of all the by-products and material that would be wasted if cows could not recycle them.
Robin R. Rastani, Ph.D., is a Dairy Technical Manager for NOVUS International, Inc. She works with dairy producers and nutritionists to provide optimal nutrition for dairy cows to ensure the cows are healthy and produce a great product for consumers. Feel free to follow her on Twitter (@cownutritionist).
Related articles
- So what do cows eat anyways? (darriecarrie.com)
- What Do Cows Eat? (Ray-Lin Dairy)
- What do Cows eat and Why? (JanicePerson.com)
- Dairy Diet – What do Cows Eat? (thedairymom.blogspot.com)
[...] to dairy cows. She is a Dairy Nutritionist and is a great source of information. Check out her post here on Just Farmers. She also wrote a guest post for Cause Matters a while ago that shows how cow feed recipes have [...]
Can all the stuff mentioned in your blog go into a compost pile, which would then be used to nourish the soil? I understand your point, that cows eat organic waste that humans can’t break down, but I don’t believe a cow is the only recycler of these wastes. Microbes, insects, worms will also break down cellulosic material; I bet some people will argue they do a better job. And by better I mean, of course, ta-dah!, “sustainable.”
I know a lot of young people who agree too. In fact, these same people believe cattle ranches and dairy farms are a waste of resources (water, feed, oil/gas).
What do you say when someone says beef and dairy production are wasteful practices in the American food production system?
One response I commonly hear from beef producers (aka farmers, ranchers): The feed that livestock eat is lower quality than the feedstuffs produced for human consumption.
Does it make sense that we produce lower quality food to feed to animals? Why not just produce high-quality feedstuffs all around, eliminate consumption by livestock, and throw the leftovers in a compost pile to be worked into the soil when it’s time to replenish spent nutrients?
Interesting perspective, Anthony. While the organic matter could be composted & applied to soil, I honestly don’t know if ALL of it could (I’ll try to track done a soil or agronomy expert for that answer).
Much of the byproduct material is high in water content, as well as minerals. Some minerals are already present in high amounts in our soils (nitrogen & phosphorus), so care must me taken when applying more of these onto soil, as high levels will impact growth of the plant, as well as possible entry into the water supply.
Lastly, termites can utilize cellulose, which is why they eat wood. I don’t believe earthworms can though. Not 100% sure… I’ll check on that too.
Thanks for your feedback!.
A Wisconsin dairy farmer left an interesting comment on my Facebook page about this post.
“Robin, thank you for this article. This is always part of my farm tour rant when we get to the feeding area, well written. I also add to my talk straw from wheat, marsh hay as we can not grow human food from that land, and I also talk about grazing cows on the foothills where no crops can grow for humans and cows are keeping the grass trimmed thus reducing fire hazard. Lets keep the list growing.”
I realized that I failed to mention some of these important factors in the blog post. Thanks to this farmer for bringing them up!