Ethanol byproducts are option for feed rations, but push your pencil first


SALEM, Ohio – Farmers are abuzz about at least half a dozen ethanol plants proposed for Ohio and western Pennsylvania.
Will they come? Will their corn demand squeeze dairy and livestock farmers’ needs dry? Can farmers use the ethanol byproducts, distillers grains, as a new feed source?
Ohio State University Extension educator David Marrison says the big ethanol push is here to stay, and will bring an opportunity for farmers to feed both wet and dry distillers grains.
“We might as well try it,” he said last week during a workshop aimed at dairymen interested in adding a new feed source to their rations.
Can’t ignore. Marrison pointed out some shocking statistics: If ethanol production estimates are correct and if the size of the U.S. cattle herd remains static, in just three years we will have enough distillers grains to feed every dairy and beef cow and calf in the U.S. about 1.5 pounds per day, every day.
Projected ethanol production in Ohio alone would allow for 8 pounds per day of the feed for 850,000 cows. That’s a whopping figure, since right now Ohio only has about 266,000 cows, Extension dairy specialist Dianne Shoemaker said.
Distillers grains can’t be ignored.
Work it out. But Marrison, Shoemaker, and dairy nutrition guru Bill Weiss all cautioned against jumping headfirst into the possibilities distillers grains offer.
Better push your pencil first, all three agreed.
Differences. Kansas State University economist John Lawrence estimates there will be about 46.8 million tons of DDGs produced annually if 5.5 billion bushels of corn are processed for ethanol.
Marrison compared that figure with the 700 million bushels of corn that already go into the U.S. dairy industry each year.
The two numbers aren’t comparable. And neither are distillers grains and straight corn.
“DDGs aren’t going to be the savior of the U.S. dairy economy,” nutritionist Bill Weiss said.
Distillers grains have a different nutritional value than corn, the experts said, and that affects how the feed can be added to a balanced ration, how cattle will utilize the feed’s nutrients, and even how farmers must manage those nutrients as they pass through the cows.
Production. Weiss said the ethanol production process takes only starch out of corn, not fiber or fat or ash. That means adding it to the ration won’t affect how much protein milking cows need from other sources, like soybean meal.
“Data shows you can feed moderate amounts [of distillers grains] and still get 80 to 90 pounds of milk,” Weiss said.
“But you can’t just take out 10 pounds of corn and soy and replace it [with distillers grains]. It’s not that simple.”
Farmers will have to figure costs on each individual ration, keeping corn and soybean meal costs in mind, and see if the pricing plays out.
In northeast Ohio and western Pennsylvania, chances are the numbers may not work out. With no ethanol facilities online yet, farmers are faced with trucking wet or dry distillers grains from out of state.
Wet distillers grain can’t be shipped easily, Weiss said, noting that it’s 30 percent water. He estimated the wet feed can only be transported 50 to 75 miles maximum.
In this region, there’s not yet an ethanol plant that could fulfill that need.
Milk makeup. Weiss also cautions that because of the way corn is heated to make distillers grains, lysine is destroyed and the final product can reduce the percent protein in the milk tank.
Heat also reduces digestibility of the DDGs.
As a feed source, DDGs are a moderate source of crude protein and high in ruminant bypass protein. Weiss also says DDGs are not a forage substitute.
In addition, if too much distillers grain is added to a ration, cows may take in too much fat. Too much fat will reduce milk production and decrease overall feed intake, Weiss said.
Watch the phosphorus. Weiss said DDGs aren’t an optimal feed for dry cows and put farmers at risk of feeding too much protein and phosphorus to cattle that don’t need it.
Excess phosphorus concentrations can affect manure management plans, Weiss said, noting high-phosphorus manure has to be spread at lower rates and over larger plots of land.
“If you have the land to spread it, it’s not an issue. But you’ve got to find some place to put the extra phosphorus and nitrogen,” he said.
Reminder. In addition to feeding concerns, there are also issues with storing distillers grains, Dianne Shoemaker said.
Though the feed mixes well into rations and may be cheaper than corn, it’s risky when it comes to storage and spoilage. Distillers grains are especially prone to molding, Shoemaker said, so even if the feed is bagged, it must be fed quickly to stay ahead of spoilage.
(Reporter Andrea Myers welcomes feedback by phone at 800-837-3419 or by e-mail at

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