The rapid growth of the ethanol industry has meant the availability of ever-increasing quantities of dried distillers grains with solubles (DDGS). Left over from the ethanol production process, DDGS is low in carbohydrates but high in protein, fat and fiber. In many areas, it’s revolutionized livestock production; rather than compete with ethanol plants for corn, feeders and cattle producers are adding DDGS to their rations.
The growth in supply and use of DDGS has prompted numerous feeding studies in recent years. One study conducted by University of Missouri scientists and ADM Alliance Nutrition sought to define optimal levels of DDGS for cattle grazing low endophyte or endophyte free Fescue. Researchers J.E. Williams and others placed 30 Angus/Simmental cross calves on endophyte-free Fescue for 90 days and supplemented them with DDGS ranging from 1.5 to 4.2 pounds per day, plus a control group that received no DDGS. They found average daily gain (ADG) responded in a linear and squared fashion with increasing levels of the supplement, and backfat increased linearly.
In a second test, the MU researchers placed 48 Charolais cross heifers on low and very low endophyte Kentucky 31 and supplemented them at between 1-3 pounds per day, plus a control group that got soybean hulls. The heifers that received 2-3 pounds per day tended toward a higher ADG than did the soy hulls control group, and dry matter intake of the forage as a percentage of body weight tended to be greater for very low endophytic than for low endophytic Fescue.
Shane Gadberry, associate professor in animal science with the Arkansas Cooperative Extension Service warned that the difficulty in storing and handling modified grains, and the need to use the feedstuff rapidly, can make it less practical for many producers, who would need to store it in bunkers and may have to add some coarse material. DDGS, on the other hand, is easy to store and feed, provided daily rations are used as a supplement and kept below 1 percent of body weight. “Cattle producers that are backgrounding cattle, or trying to substitute grains for forage during drought, should keep distillers grains below 40 percent of the diet dry matter content to reduce chances for health problems caused by excessive sulfur in the diet,” Gadberry said.
The price of DDGS is based more on its energy than protein content, and its abundance has made it a very competitive ingredient compared to corn gluten feed or soybean hulls. In addition, the cattle prefer it, and cattle buyers have seen some benefit from getting cattle to eat receiving diets quickly. Another option for producers is distillers solubles, the liquid byproduct of ethanol production, which can be added to total mixed rations to provide nutrients as well as moisture to help reduce dustiness of mixed feeds. However, producers should take into account the high water content when determining whether distillers solubles are price competitive. Gadberry said some producers have also tried to make free choice slurries available, but high intakes can cause sulfur related health problems.
Gadberry said U of A has also conducted several trials using DDGS as a supplement. A rate of 0.3 percent of body weight was more efficient than was 0.6 percent for growing cattle on summer pasture, but targeted rates of gain for marketing or breeding also have to be considered in deciding the best supplementation rate. He said, “Improved forages in Arkansas, such as Bermudagrass, can have a moderate to high protein content, but the high fiber content can limit rate of gain. The energy value of distillers grains is probably benefiting these cattle most. The protein in distillers grains is a higher rumen bypass protein; cattle may benefit from this; however, research with other rumen bypass proteins on improved forages suggest that bypass protein may not be any more beneficial than providing energy.”
