Wet byproducts from ethanol production are tricky to store for later use as cattle feed because of their high moisture content and threat of spoilage, but mixing them with drier, bulkier feeds improves storability, according to University of Nebraska-Lincoln research.

UNL animal scientists have just completed research that devised formulas for mixing several widely available dry forages with wet distillers grains. Their findings could help feedlot managers and cow-calf producers purchase wet distillers grains during the summer when their plentiful supply can mean lower prices and safely store them for use later in the season, or for winter feeding.

The relatively short shelf life of wet distillers grains has been a key obstacle to their use as feed in some situations, said Galen Erickson, a UNL beef nutritionist. Feedlots need to have the material delivered frequently and use it within a few days to avoid spoilage; for smaller operations, that's not economically feasible. Cow-calf operators, meantime, have greatest use for the feed during the winter, but that's when supplies tend to be lower than during the summer.

At 65 percent moisture content, wet distillers grains alone cannot be stored in silage bags or bunkers like corn silage or bulkier feeds. Compressing them in bags to push out air and prevent spoilage splits the bags, and they're too wet to be compacted by tractors in bunkers.

UNL animal scientists experimented with mixing grass hay, alfalfa hay and wheat straw with the wet distillers grains to determine how much dry material would be needed for successful storage. For bagging, they compressed them at standard pressure, 300 pounds per square inch.

"Other fiber sources would presumably work, but we chose these three because of their availability this time of year," said Erickson, who worked with Terry Klopfenstein, a UNL beef nutrition researcher on the project.

When bagging silage, the Institute of Agriculture and Natural Resources researcher said, the research established the following minimal levels of dry material: 15 percent for grass hay; 22.5 percent, alfalfa hay; and 12.5 percent, wheat straw. Erickson noted that those percentages are on a dry basis, which is different than the amounts actually weighed out when mixing.

Researchers also experimented with mixing dry distillers grains and wet corn gluten feed, another ethanol byproduct, with the wet distillers grains. A 50-50 blend of dry and wet distillers grain bagged up well, while a 60-40 mixture of wet corn gluten and wet distillers grains seemed to work.

Erickson noted that two ethanol plants in Nebraska – in Central City and Plainview – produce modified wet distillers grains, which has a moisture content of 50 to 55 percent. That material is dry enough to bag without mixing in other materials.

For bunker storage, Erickson said, a mix of 40 percent grass hay and 60 percent wet distillers grains was firm enough to allow enough packing. With wheat straw, he recommends 25 to 32 percent of the dry material. There may be a 2-3 inch layer of spoilage at the top of the pile, but what's underneath seems to be fine.

More information on the use of ethanol byproducts for feed is available in "Utilization of Corn Co-products in the Beef Industry," a joint publication of the university's Institute of Agriculture and Natural Resources and the Nebraska Corn Board. It's on the Web at UNL's beef cattle production site, http://beef.unl.edu. Click on the By-product Feeds link on the left side.

UNL's byproduct feeds research is conducted in cooperation with the university's Agricultural Research Division with funding from the Nebraska Corn board and ethanol/corn processors Cargill, Abengoa Bioenergy and Dakota Gold. The current storage trials were conducted with Chief Ethanol, Hastings; ADM Milling, Columbus; and Platte Valley Fuel Ethanol, Central City.