How a Roller Mill Affects the Nutritional Value of Grains for Livestock
Updated: Aug 2
If you are looking to maximize the gain from your grain, you have to process it before feeding it to your cattle. This helps your livestock better digest the nutrition in the grain so that they can utilize it more efficiently. This helps them get what they need out of the grain in their complex digestive process.
However, you might have heard that milled grain is not as nutritious as whole grain. This is true in some situations, but it's a simplification of a complicated issue. Do not let confusion on this issue keep you from processing grain before feeding it to your livestock.
While there are many processing methods that can help your livestock take advantage of the nutrition in grain, a roller mill is usually considered the best. That's because a roller mill is efficient and does not change the nutrition content of your grain, just makes it more available to your livestock. On the other hand, a hammer mill can lead to a loss of some important nutrition.
The Challenge: Getting Past the Seed's Defenses
The basic challenge in feeding grain to livestock is that the plant has done everything it can to keep animals from digesting the grain. The grain is the plant's seed, which means it's the next generation, and the plant's survival depends on as many of those seeds as possible passing safely through the digestive tract of any animals that might eat it. To protect the seed, the plant has given it a tough outer coating called a hull. Without processing, a high amount of grain--nearly 50% in some cases--will go through an animal without being digested.
Milling grain breaks up the hull and makes it more digestible for the animal. How digestible the grain becomes depends on the milling technique and the grain itself.
Roller Mills Increase Availability of Nutrition
When grain passes through the roller mill, it gets crushed between the rollers, which breaks up the seed. This causes the hull to compress and usually to break. Once the hull is broken, the starch and other nutrients inside the grain become much more available to your livestock.
How much does rolling increase availability of starches? A lot. In barley, only about 50% of the starch is available in the whole grain. But when barley is rolled, the starch availability increases to 95%. Corn is already fairly digestible, with a starch digestibility of about 85% as whole kernels, but that can also increase to around 95% for high-moisture rolled corn.
Since feed is your largest expense in running a livestock operation, increasing the effectiveness of your feed by even 12% in the case of corn can make a big difference. It can lead to increased daily gain for beef cattle or improved milk production for dairy cows, and that means profitability for your livestock operation.
Without Sorting Overall Nutritional Value Does Not Change
So if processing grain can be good for your livestock, why are we constantly being told to avoid processed grains and favor whole grains? The difference is that when you're milling grain for your livestock, you keep feeding the entire grain to the animal. You crack, compress, or grind the corn, wheat, barley, or oats, but you don't take anything out. That's very different from the way processed grains are handled for human consumption.
The key issue in human grain consumption is white flour. White flour is made in a multi-step process. During the early stages of the process, millers remove the bran and the germ of the seed. The bran, a coating of the seed that's just under the hull, and the germ, the living plant within the seed, are removed because they contain fat, which can make the grain spoil.
Unfortunately, the bran and the germ contain a lot of important nutrients. The grain is enriched to replace some of those nutrients, but other things, like fiber, are not always replaced.
However, if you process grains with a roller mill, but continue to feed all the parts to your livestock animals, they will get all the nutrients from the grain, and get them more efficiently thanks to milling.
Hammer Mills Can Change Nutritional Value
While roller mills work by simply crushing the grain, largely passing the entire grain through, hammer mills are different.
Hammer mills work by spinning one or more hammers inside a cage or screen. As the hammers spin, they contact the grain, smashing it, which can break it up quite effectively. Hammer mills can quickly turn grain into very small particles. The screen on the outside of the hammer mill determines the largest particle size that will exit the mill, but there are also many smaller particles that will come out. In fact, a lot of the grain is transformed into dust. This dust is hard to manage, and it tends to accumulate around the mill, or else it's sucked away from the mill for safety--too much dust can lead to fires and explosions.
The problem is that the dust is not just dust, it's part of the grain. Some parts of the grain are more likely to turn into dust, such as the endosperm--which contains most of the energy-rich starch--and the protein rich germ and aleurone layer of the bran. This means that the dust produced by hammer mills is more of a waste. If animals eat it, it can contribute to ulcers and other digestive problems. But if it blows away, or doesn't make it into the feed, it carries with it essential nutrients that the animals will miss.
Find the Best Mill for Your Operation at Automatic
For nearly 100 years, Automatic Equipment Manufacturing has been helping farmers find the best equipment to process their grains for livestock. If you have questions about your operation, we can help you find answers--and direct you to the right roller mill for you. Whether you're a small hobby farm or a huge feedlot operation, Automatic has a mill to meet your needs.
Please contact us today to talk about how best to feed your livestock.