Frequently Asked Questions about DDGS
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- About DDGS
- Cost and Quality
- Use in Animal Diets
- Storage and Handling
What is corn distillers dried grains with solubles (DDGS)?
- Corn distillers dried grains with solubles (DDGS) is the product obtained after the removal of ethyl alcohol by distillation from yeast fermentation of a grain or a grain mixture by condensing and drying at least three-fourths of the solids of the resultant whole stillage by methods employed in the grain distilling industry.
- DDGS is produced by blending corn distillers liquid solubles on the wet corn distillers grains before being dried. If not dried, it is sold as wet distillers grains (WDG).
- American Feed Control Officials (AFCO) Number 27.6
- International Feed Number (IFN) 5-02-843
- DDGS can also be produced from other grains, such as barley, rye, sorghum and wheat.
For typical analysis (average nutritional profile) of the two products, see Product Descriptions.
What are the differences among DDGS, corn gluten feed and corn gluten meal?
- DDGS is a co-product of the dry milling manufacturing defined in the previous answer.
- Corn gluten feed is a co-product of wet milling manufacturing. It is defined as that part of the commercial shelled corn that remains after the extraction of the larger portion of the starch, gluten and germ by the processing employed in wet milling manufacture of corn starch or syrup.
- Corn gluten meal is a co-product of wet milling manufacturing. It is defined as the dried residue from corn after the removal of the larger part of the starch and germ, and the separations of the bran by the process employed in the wet milling manufacture of corn starch or syrup, or by enzymatic treatment of the endosperm.
- Corn gluten feed is significantly lower in energy, protein and fat, than DDGS and therefore is valued lower than DDGS in many diets.
- Corn gluten meal is used as a protein source in poultry and livestock feeds. It also serves as a good source of xanthophylls (golden yellow).
The table below is a comparison of the major nutrient analysis from NRC for swine.
| DDGS | Corn Gluten Feed | Corn Gluten Meal | |
| Metabolizable Energy, Kcal/Kg | 2820 | 2605 | 3830 |
| Crude Protein | 27.7% | 21.5% | 60.2% |
| Crude, Fat | 8.4% | 3.0% | 2.9% |
| Calcium | 0.20% | 0.22% | 0.05% |
| Phosphorus | 0.77% | 0.83% | 0.44% |
What is the nutrient analysis of DDGS?
A rule of thumb for the nutrient analysis
of DDGS is that it is approximately three times the nutrient analysis
of corn. Additional nutrient analysis is available upon request. The
following table shows the results from a sampling of 10 plants for
one year (total of 118 samples).
| Nutrient | 88% Dry Matter |
| Metabolizable Energy (kcal/lb.) | 1500 |
| Crude Protein | 26.6% |
| Crude Fat | 9.6% |
| Crude Fiber | 7.7% |
| Calcium | 0.05% |
| Total Phosphorus | 0.78% |
| Available Phosphorus | 0.67% |
| Sodium | 0.21% |
| Total Lysine | 0.73% |
| Digestible* Lysine | 0.387% |
| Total Threonine | 0.99% |
| Digestible* Threonine | 0.545% |
| Total Tryptophan | 0.21% |
| Digestible* Tryptophan | 0.134% |
| Total Methionine | 0.48% |
| Digestible* Methionine | 0.283% |
What are the major ingredients that
affect the cost of DDGS?
The value of DDGS nutrient contribution to the final diet is
basically determined by the cost of corn, soybean meal, and dicalcium
or monocalcium phosphate for which DDGS is substituted when added
to the diet.
How consistent are the various product
characteristics of DDGS?
The particle size, color, bulk density
and nutrient analysis can vary slightly from plant to plant. The recommended
purchasing practice to optimize the consistency of DDGS is to purchase
DDGS from one plant or selected plants. The
factors that can be involved include:
- The equipment used for drying and temperature used during drying. The drum dryers produce a more granular product whereas the flash dryer produces a finer particle DDGS. The resultant DDGS particle size produced will affect bulk density.
- Source of corn and final ratio of wet corn distillers grains to corn distillers liquid solubles going into the dryer can affect nutrient analysis.
- Typical bulk density is 35 to 36 lbs/cubic foot.
- The typical color of DDGS is generally in the range of "golden." If the color is "dark brown or darker," it would be an indication that the drying process overheated the DDGS and would reduce the digestibility of the amino acids.
What research has been done on DDGS
from ethanol plants?
Swine, poultry, dairy and beef researchers from several land
grant colleges have conducted several experiments to evaluate the
use of DDGS in feeding programs. Many of these experiments have been
summarized and reported at various animal and poultry science meetings.
The results of these experiments are reported on the website www.ddgs.umn.edu.
Does GMO corn affect the quality of
DDGS?
Currently, ethanol plants do not
differentiate between GMO and non-GMO corn. Research that has been
done with GMO corn suggests that it would not affect the quality of
resultant DDGS.
Can DDGS be pelleted?
Yes. However, obtaining a high-quality
pellet may require a different die than the dies typically used to
pellet corn-soybean meal diets.
Where can I purchase distillers grains
in Iowa?
For a list of marketers who sell distillers grains in Iowa, see Key
Contacts and Resources.
What livestock species provides the
greatest value for DDGS?
Ruminants, especially dairy, provide
the greatest value because of the nutrient contribution and the bypass
protein of DDGS.
What are the major nutrient guidelines for the use of DDGS in nonruminant diets?
- Use the available phosphorus value because the bioavailability of phosphorus is 85% in DDGS, which is higher than the bioavailability of phosphorus in corn of 14%, 31% in 44% soybean meal, or 23% in 47% soybean meal.
- Use digestible amino acid values to more accurately balance the amino acid requirements of the animal when incorporating DDGS into the diets.
What levels of DDGS are being used
in nonruminant diet formulations?
A common level is 10% in many nonruminant diets. However,
research has shown that DDGS has been successfully incorporated into
swine diets up to 20%, and has resulted in similar performance and
carcass characteristics as pigs fed a typical corn-soybean meal diet.
Do DDGS provide any added values when
used in swine diets?
Research to determine these added
values is ongoing. Many field reports indicate improved "gut health"
of growing-finishing pigs.
Can phytase be added to diets that
contain DDGS?
Yes, research has demonstrated that
phytase added to typical corn-soybean meal diets (at 225 FTU/lb. of
complete feed) replaces approximately 10 to 11 lb/ton of inorganic
phosphorus and reduces phosphorus excretion in the manure by approximately
30%. The addition of 10% DDGS to the diet replaces approximately 6
to 7 lb/ton of inorganic phosphorus.
Are there special precautions for handling and storing wet or dry distillers grains with solubles?
- Generally, DDGS will contain approximately 12% moisture or less. Therefore, when properly stored the quality of DDGS will be maintained, as well as any other protein or grain ingredients used in diet formulations.
- Flowability agents may be used to enhance flowability of DDGS, especially if the DDGS is of the finer particle size or contains excessive moisture.
- Properly processed and stored DDGS does not require the use of antioxidants or mold inhibitors.
- Wet corn distillers grains with solubles, which contains approximately 65% to 70% moisture, is the product available before being dried. "Modified wet DDGS," which contains approximately 50% moisture, is also available from some plants. Additives are available from commercial suppliers to enhance the storage life of the wet corn distillers grain with solubles. Practical experience suggests that an open storage time of approximately a week, depending on environmental temperature, can be maintained without product deterioration.
What is the risk of mycotoxins in DDGS?
- The fermentation process in an ethanol plant does not destroy mycotoxins that may be present on the incoming corn. A rule of thumb is that if incoming corn contains 1 ppm of a mycotoxin, the resultant DDGS will contain approximately 3 ppm.
- Generally the purchasing quality control specifications of corn at an ethanol plant are similar to those used at a grain elevator or terminal.
- Keep mycotoxin values in prospective. Tolerance levels are based
on mycotoxin levels in complete feed.
- If corn contains 1 ppm of mycotoxin, and a typical swine diet contains 80% corn, the mycotoxin level in the complete diet would be 0.8 ppm.
- If DDGS contains 3 ppm of mycotoxin, and a typical diet contains 10% DDGS, the mycotoxin level in the complete final diet would be 0.3 ppm.