Noting that energy density in growing diets could affect carcass characteristics, researchers from Ohio State University and the University of Wisconsin conducted a trial to evaluate the source, specifically dried distillers’ grains with solubles for growing cattle. The team split a group of 144 Angus-cross steers into three groups based on initial weight, then split those groups into four treatments, feeding 24 pens of six steers each for 98 days. The treatments included these feeding systems:
* 65 percent DDGS fed to gain 2 pounds per day
* 65 percent DDGS fed to gain 3 pounds per day
* 65 percent corn fed to gain 2 pounds per day
* 65 percent corn fed to gain 3 pounds per day
After the growing period, researchers placed the steers on the same finishing ration and fed them until the large group averaged 1,200 pounds, the medium group averaged 1,150 pounds and the small group averaged 1,100 pounds.
Consistent with other studies, compensatory gain resulted in the groups fed for lower gains during growing, having higher average daily gains during finishing. The source of energy during growing did not affect finishing gains. After finishing, steers grown with the lower-gain ration had less fat cover, numerically lower USDA yield grades and larger ribeyes. The group fed corn for 2 pounds of daily gain during growing had the highest marbling, and those fed DDGS for lower gain had the lowest marbling. Among the groups fed for 3 pounds of daily gain during growing, the corn-fed steers had lower marbling than the corn-fed steers in the lower-gain groups. Conversely, among the DDGS groups, those on the ration targeting 3 pounds of daily gain during growing had higher marbling than those on the lower-gain growing ration. So, feeding the DDGS-based diet to achieve faster gains during the growing phase increased marbling, whereas feeding the corn-based diet to increase faster gains during the growing phase decreased marbling.