Optimum Level of Dried Distillers Grains in a Finishing Diet was 20 Percent

June 2007

A finishing study was conducted at the Univ. of Nebraska to determine optimum levels of dry distillers grains with solubles (DDGS) in a corn-based diet on steer performance. A total of 250 crossbred backgrounded steer calves (676 lb) were allotted to six different dietary levels of DDGS: 0, 10, 20, 30, 40, and 50 percent. Metabolic adaptation to these diets included a 22-day step-up period followed by a 145-day finishing period. At the end of the 22-day step-up period, sulfur content of DDGS resulted in toxic dietary sulfur levels for the 50 percent DDGS treatments (0.6%) which is higher than the threshold level for dietary sulfur (0.4%). As a result, nine steers died or were removed from the trial. Consequently, the 50 percent treatment was dropped from the study. The following table summarized results for the 145-day finishing period.

Percent of DDGS in Diet
Item 0 10 20 30 40
Dry matter intake, lb 20.8 21.8 20.8 21.2 20.7
Avg. daily gain, lb 3.29 3.55 3.71 3.56 3.56
Final body wt., lb 1230 1266 1297 1273 1258
Feed/gain 6.32 6.15 5.60 5.93 5.77

As shown above, there were no significant differences in dry matter intake. Average daily gain and final weight peaked at 20% DDGS and declined thereafter. This resulted in an improvement in feed conversion up to the 20% level followed by a decrease. Although not shown here, except for carcass weight, there were no differences in carcass characteristics. These results showed that addition of DDGS can improve finishing performance at any level ranging from 10 to 40% of dry matter, with the optimum level at 20% (Buckner et al. 2007. Univ. of Nebraska Beef Cattle Report).

Rick RasbyDr. Rick Rasby, Professor of Animal Science
Animal Science, University of Nebraska–Lincoln, Lincoln, NE