Research: Distillers grains energy value differs with feedstock

By Susanne Retka Schill | May 09, 2008
Web exclusive posted May 13, 2008 at 2:16 p.m. CST

The ethanol feedstock makes a difference when feeding distillers grains coproducts, according to Texas AgriLife Research. Jim MacDonald, beef nutritionist with the research and extension center in Amarillo, Texas, conducted two years of trials to investigate the dramatically different animal performance responses observed in the Northern Plains and Southern Plains distillers grains feeding trials.

"There are two obvious differences in research conducted in the two regions," MacDonald said. "Researchers in the Northern Plains tend to use dry-rolled corn, and in the Southern Plains, they use steam-flaked corn-based diets." Additionally, research in northern states used distillers grains from corn, whereas the southern research included distillers grains from sorghum.

"Our study in feeding sorghum distillers grain at 25 percent of dry matter, showed the energy value for that product was 73 percent of the value of steam-flaked corn," he said. In contrast, the performance trial with corn-derived distillers grains from Nebraska suggested the energy value was roughly equal to steam-flaked corn. The variations in the energy value of distillers grains is similar to the difference in the cereal grains used as the ethanol feedstock, he explained.

MacDonald also found there is an advantage to flaking corn when adding distillers grains to the ration, a practice common in feed yards in the Southern Plains to increase the amount of available energy in the feed.

Data is being developed by MacDonald and other researchers concerning the effects of changes in distillers grains processing. "The more they understand what goes on in that ethanol plant, the better chance they'll have of accurately valuing the production," he said. "Clearly the most important question is what cereal grain is being used. But they also need to know about control measures for things like sulfur content and are the solubles being added back at a consistent rate."