From the September 2016 issue of Drovers.

The incoming bumper corn crop projected by USDA for this fall will open doors for producers to use the increased availability of corn and corn distillers grain for cattle feed.

According to University of Nebraska-Lincoln cow-calf range management specialist Karla Jenkins, producers need to weigh the differences between the two commodities when using them to supplement pasture cattle.

“One of the big differences between corn and corn distillers grains is the starch content. Corn is about 73% starch while corn distillers grains has only trace amounts of starch since it is used for the ethanol production,” she says. “This is important because starch can have negative impacts on fiber digestion because it shifts the microbial population in the rumen away from fiber digesters. Obviously, if cattle are grazing grass they need to be able to effectively digest grass.”

When used in roughage based diets, the total digestible nutrients (TDN) for corn is only 83%, Jenkins says, compared to corn distillers 108% digestibility because of fiber and corn oil content. “This may seem surprising,” she adds, “but the protein and oil in distillers grains is concentrated and both have more energy than starch.”

Because corn is high in starch and has a crude protein content of 10%, compared to distillers 30%, supplementation like alfalfa will likely be needed when used in low quality forage diets, Jenkins says.