May 15, 2007

Corn distillers' grain, a new trend in US livestock feed

The increased supplies of corn distillers' grains (CDG) could serve as a hopeful prospect for livestock producers in the wake of rising corn prices over deluge for ethanol, according to Dave Beede, a dairy nutrition specialist from Michigan State University.

Beede said from a research standpoint, a lot of things have to be known to effectively feed distillers grains.

For livestock farmers considering feeding CDG, Beede said nutrient profiles as CDG and number 2 yellow corn grain differ in two main ways: 1) Starch content in CDG is low because it is the feedstock for ethanol; 2) Nutrient concentrations are typically three to four times greater in CDG than in corn grain.

Consistency is a major consideration, Beede says and composition of CDG can vary from plant to plant and batch to batch to make routine analysis for nutrient composition of purchased CDG extremely important.

Beede said some research said incorporating CDG in rations can be at 20 percent dry matter. Factors to consider should include overall ruminal fermentability of the ration, types of forages (corn silage versus alfalfa) and other ration ingredients, amounts of unsaturated fat and stage of lactation and milk production level of cows.

Beede suggests taking a gradual approach from the beginning. As an average, consider limiting CDG to 10 percent of ration DM and 5 percent for higher-producing or early lactation cows. While on the process, monitor feed intake, milk yield and composition. Beede said if it appears economically feasible to put more CDG in the ration, make additional adjustments and continue to monitor and evaluate.

Ethanol plants often add condensed solubles to produce the end byproduct (both wet and dry CDG.) and depending on the amount of solubles added, the levels of fat, phosphorous and sulfur can increase. According to Beede, implications from both a nutritional standpoint [ration balancing] and an environmental standpoint [excess phosphorus in manure], can occur.

Beede said incorporating CDG in rations with higher concentrations of very fermentable ingredients like corn grain (ground or high moisture) and corn silage can reduce ruminal acidity, feed intake and milk yield. In combination with excess polyunsaturated fat (like the corn oil found in CDG), reduced fat test and yield can occur.

With wet distillers grain, Beede said, there can be variations in dry matter content from load to load. Requiring the ethanol plant to meet a specific target for dry matter content is a wise business practice.  Beede advises to set up a payment schedule to adjust price downward when CDG are below the target DM.