MSU to study nutritional value of DDGS

Animal nutritionist Brian Rude of the MSU Department of Animal and Dairy Sciences, and his graduate student, Jonathan Greene of Trussville, Ala., conducted a digestibility study of refined distillers grains on steers at MSU’s South Farm. The refined version has a higher concentration of fiber. The Mississippi Agricultural and Forestry Experiment Station (MAFES) funded their research, which holds promise for cattle producers and feed manufacturers.

MAFES bioenergy scientist Radhakrishnan Srinivasan developed a technique he calls the “elusieve” process to use sifters and air to separate the fiber in distillers grains from the protein and fat. Some of these nutrients still cling to the fiber particles afterwards. Srinivasan supplied the researchers with unrefined and refined versions of distillers grains for the study. “If we can use a byproduct that humans can’t eat to produce food that they can, we’re doing a successful job of recycling,” Rude said.

Trial
In the trial, twelve steers were divided into three groups of four and placed in holding pens. One group was fed a ration containing refined distillers grains, which the researchers designated as the L-fraction, or lighter density fraction. A second group of steers was fed a ration containing unprocessed distillers grains, and a third was given a control ration equivalent to commercial feed.

Results
Interestingly, the results indicated the steers fed the L-fraction ration were able to digest a greater percentage of protein than those on the other two diets. Fat digestibility was similar between the unprocessed distillers grains and the L-fraction, but generally better than the control diet.  Perhaps even more significant, the steers that ate the L-fraction ration consumed less feed than those on the unprocessed distillers grains ration and those eating the control diet. The L-fraction diet resulted in steers eating less but digesting more protein.

“The nutrient digestibilities for all three groups were comparable and there were no significant differences among the different rations,” Rude said.  Future studies of refined and unrefined distillers grains may lead to the identification of potential ingredients for cattle feeds that are cost effective and may even enhance weight gain.