Corn By-Products Are Not Equal
Mike Hutjens
Extension Dairy Specialist
University of Illinois, Urbana
Corn distillers grain will continue to be availability and represent “good buys” for dairy managers and feed consultants. With continued effort to market distillers grains, ethanol plant managers are refining their methods by extracting more starch for ethanol production. Another approach is to evaluate the corn by-products to determine if more value can be derived while providing feeds that can fit in modern dairy rations at higher levels.
At the World Dairy Expo in Madison, WI, I visited a booth sponsored by Badger State Ethanol, Monroe, WI. This group is exploring a new process leading to several new corn by-products and does not use supplemental sulfur dioxide (can affect feed palatability and cause corrosion). Table 1 lists several potential new products including corn germ, corn bran, modified corn gluten meal, and modified dried distillers grain (DDG). “Typical” DDG is listed for comparison.
| Germ | Bran | Gluten meal | Modified DDG | "Typical" DDG | |
| Crude protein | 17 | 10 | 45 | 30 | 27 |
| Fat | 45 | 2 | 3 | 3 | 9-15 |
| Fiber | 6 | 17 | 4 | 8 | 8 |
| Starch | 8 | 6 | 2 | 4 | not listed |
| Ash | 2 | 1 | 4 | 2.5 | 4.4 |
Corn germ could be a premium product that may be sold to corn oil processors. It contains a significant amount of phosphorous. Bio-diesel could be an alternative use for the corn oil.
Corn bran is a feed that ruminants could ferment and digest (similar to citrus or beet pulp). For dairy producers, this product could be used to replace lower quality forages, represent a cheaper soy hull replacement, and/or dilute starch found in corn silage based dairy rations.
Modified corn gluten meal is more applicable as swine and poultry feed (source of pigmentation). The energy content is similar to high protein soybean meal, but does not contain higher fiber content that is important for swine and poultry diets.
Modified DDG would be similar to “typical” DDG, but it is lower in oil that can lead to rumen fermentation challenges and lower milk fat test. For dairy managers, this product may allow for higher levels of inclusion of modified DDG compared to “typical” DDG.
As ethanol production plants and products come on-line, dairy and beef managers will need to carefully consider which corn by-products are available, the break-even price of each product, and strategy to balance rations with corn products used. New corn co-products will be a valuable tool for dairy nutritionists and managers for the following reasons.
- •Lower levels of oil will allow higher inclusion levels
- •Less phosphorous may allow higher manure application rates avoiding high soil levels of phosphorous
- •A source of digestible fiber that is lower in protein compared to “typical” DDG
