Research »   Distillers' Grains

Distillers' Grains

Distillers’ grains are a by-product from the process of grain-based ethanol production and can be used as an economical commodity in feeding cattle. As long as bioethanol production continues at current levels, the feedlot industry in Canada will feed distillers’ grains in order to produce beef as efficiently as our trading partners. Most distillers’ grains in North America come from corn with some from sorghum and wheat. Corn distillers’ grains are sold produced in Eastern Canada and the U.S. Wheat distillers’ grains, or a mixture of wheat and corn, are produced in Western Canada.


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Production and Types

Distillers’ grains are the major by-product from the production of ethanol. To produce biofuels, cereal grains are heated and fermented. The starch is converted into ethanol and removed. The mixture of concentrated protein, fibre, oil and minerals, which remains is called stillage.

Stillage is sold either wet (20 to 30% dry matter) or dry (90% dry matter). Stillage remaining after the fermentation and distillation process is low in solids and is sometimes fed directly to livestock through the watering system (thin stillage).

Bioethanol production will generate approximately 1.8 million tonnes of dried distillers’ grains with solubles (DDGS) in North America this year.

Typically, stillage is further separated into distillers’ grains and solubles. Solubles are recovered and incorporated into the distillers’ grains, called distillers’ grains with solubles (DGS). DGS can be used wet (WDGS) but is often dried (DDGS) in order to reduce

DGS = Distillers' grain with solubles 
DDGS = Dried distillers' grains with solubles
WDGS = Wet distillers' grains with solubles  

shipping costs.

Composition

There is considerable variation in the composition of distillers’ grains. Composition may be partially reflected by whether grain is processed by dry or wet milling before it is fermented.

Because starch is almost completely removed in the process to distill ethanol, concentration of other components, except calcium, is enhanced significantly. For example, fat, protein, fibre, phosphorus and sulfur are roughly are three times as concentrated in DDGS than in the original grain.

distller's grains with solubles
Steer after consuming 40% corn DDGS diet.
Photo credit: Lee-Anne Walter
COMPOSITION OF DISTILLERS' GRAINS* AND PARENT GRAIN, % DRY BASIS**
 Corn distillers’ grainCorn grainWheat distillers’ grainWheat grain
Protein 29.4 to 32.0 9.8 30.6 to 44.7 14.2
Crude fat (oil) 10.0 to 11.8 4.1 3.7 to 4.4 2.3
Fibre (NDF) 34.1 to 48.1 10.8 22.7 to 36.5 11.8
Calcium 0.02 to 0.03 0.03 0.02 to 0.03 0.05
Phosphorus 0.68 to 1.10 0.32 0.83 to 0.95 0.44

*Encompasses both wet and dry distillers’ grains

** Corn and wheat distillers’ values from Lethbridge Research Station, University of Saskatchewan and Spiehs et al. Journal of Animal Science (2002) vol. 80, p.2639. Grain values from NRC, Nutrient Requirements of Beef Cattle (2000).

Dietary starch, fibre and protein levels can affect the pH of a ruminant’s digestive tract, which may in turn affect how well various microbes survive and compete in the animal’s rumen, intestine and manure. This can effect animal health and welfare, food safety and feed efficacy.

The manner in which DDGS are dried can also affect nutritional value. Due to the various factors (grain type, moisture, solubles, milling and drying) that can influence composition, chemical analyses are recommended before using these by-products to feed beef cattle.

40% wheat ddgs diet
40% Wheat DDGS diet
Photo credit: Lee-Anne Walter

Receiving and Handling

DDGS can be transported and handled as any grain commodity. It is uneconomical to transport WDGS any great distance from a biofuel plant.

WDGS may deteriorate quickly in the open. WDGS may be stored for many months with under 10% loss of nutrients if:

  • In a bunker silo (either alone or in combination with wet processed grain or forage)
  • With effective ensiling practice
40% wheat ddgs diet
40% Corn DDGS diet.
Photo credit: Lee-Anne Walter

Feeding

DDGS and WDGS are both very palatable when mixed into a complete feed, or fed as a supplement that is top-dressed onto the base diet.

DDGS and WDGS can be fed without mixing into a ration, preferably from troughs but also off frozen ground, as a forage supplement.

Feed Attributes

DDGS are widely used in feedlot rations throughout North America because it reduces feed costs. The expansion of North America’s ethanol industry has increased feed grain costs and subsequently increased the use of distillers’ grains as livestock feed.

DGs can be a valuable source of dietary protein or energy for cattle, depending how they are fed.

At levels generally below 15% of the diet, dry basis, DGS is an excellent alternative to soybean or canola meal as a protein supplement. DGS is relatively high in rumen bypass protein with DDGS having slightly more than WDGS. This can mean that when there is a protein deficit from the basal diet, corn and wheat DGS can be more effective than soybean or canola meal in meeting the protein requirement of calves with a high protein demand, e.g. light weight and rapidly growing.

DGS should not exceed 50% of a feedlot diet, because fat content of the complete diet for feedlot cattle should not exceed 6%.

At levels up to 50% of the diet, dry basis, DGS is an excellent source of energy. Once the animals protein requirements have been met, excess dietary protein is used for energy instead.

Due to the high levels of fibre in DGs, there has been interest in using DG in place of dietary roughage. However, the DG fibre particles are too small to effectively maintain proper rumen function and health, and have been associated with increased incidence of rumen acidosis and liver abscesses.

A recent Canadian study found that 10% barley silage in a diet containing wheat DGS was a minimum to prevent a rumen pH drop (increased acidity) in calves fed barley diets supplemented with wheat DGS.

Benefits for feedlot cattle

Corn WDGS enhances feed efficiency of corn-based diets by up to 13% with response proportional to the level in the diet up to 50% (dry basis). Corn DDGS enhances feed efficiency up to 5%, with the maximum response from between 10 and 20% inclusion in the diet.

At dietary inclusion rates up to 20%, wheat DDGS gives similar feed efficiency to a barley-based control. Above 20% inclusion, wheat DDGS has had no effect or caused a slight decline in feed efficiency, by up to 9%.

Concerns for feedlot cattle

Phosphorus (P) levels are high in DGS. Diets containing DGS must be fortified with additional limestone over the amount used in grain diets to provide a calcium (Ca) to P ratio of at least 1.1 to 1, and preferably 1.5 to 1.

Urinary calculi is a symptom in male cattle of failing to balance the Ca:P ratio correctly.

Sulfur (S) levels are high in DGS and quite variable (0.35 to 1.4%). Levels of S in the diet above 0.4% can be toxic to feedlot cattle. S toxicity has not become a major problem so far with feeding DGS and has been the subject of a recent research project funded by the BCRC (see below).

One of the symptoms of S toxicity in feedlot cattle, especially those fed barley based diets, is polioencephalomalacia.

Because mineral levels in diets containing DG often exceed animal requirements, manure from cattle fed DGS are unusually high in nitrogen (N) and P. In the application of cattle manure from DGS fed cattle to agricultural land, P is usually the nutrient that will limit the amount of manure that can be applied to avoid P run-off and leaching into groundwater. Nutrient management programs can be used to take soil and crop requirement into account in good management of manure from feedlot cattle.

Land required for the application of feedlot manure is increased when DGS is fed.

 

Feeding DGS to feedlot cattle does not consistently affect carcass grade and meat quality. However, there are two points worth noting:

  • Some studies have shown that DGS inclusion decreases marbling of meat but this is not a consistent finding and it cannot be easily explained.
  • Feeding DGS negatively affects meat colour and colour stability of beef in the retail case but significance of this in affecting consumer satisfaction is less clear. This effect of feeding DGS in feedlot diets can be counteracted by providing additional vitamin E.

There have been concerns that using DGS in feedlot diets may increase shedding of E. coli 0157.H7. However,  results have been conflicting and results of some studies, including a recent one in Canada, have not confirmed this finding. Many factors affect shedding of E.coli 0157.H7 by feedlot cattle. With quality control during processing, beef from cattle fed DGS is as safe as beef from cattle fed conventional diets.

Feeding distillers’ grains to backgrounding cattle

DGS is an excellent energy and/or protein feed to use in completely mixed rations for backgrounding cattle for the feedlot. Calves fed forage/barley grain diets in western Canada where wheat DDGS has replaced most of the barley grain have performed equally to calves on the forage/barley control.

DGS can be an ideal supplement for calves grazing summer pasture, stockpiled wheat or other forage in the late fall and early winter before being shipped to the feedlot.

Feeding distillers’ grains to cow-calf

DGS is an excellent energy source for supplementing any type of forage fed to cows and calves. Cows in mid-lactation have been fed as much as 15 kg of WDGS daily. Precautions noted for feedlot cattle regarding P and S must be noted in the feeding of DGS for cow-calf.

Canadian Research on DGS

Extensive research on distillers’ grains has been ongoing in the U.S. for decades. Canadian research work to determine if American results differ under Western Canadian conditions, since most Canadian feedlots are in the Western provinces, and to study the types of grains that are more typically used in finishing diets in Canada.

Recent Canadian research has studied the effects of wheat, barley and oat DGS, regional differences, and effects on nutrient value of manure.

Learn More

To learn more on this topic, see the fact sheets posted on the right side of this page. External resources are listed below.

Wheat DDGS Feeding Guide (1st Edition, 2011)
Feed Opportunities from Biofuel Network
http://www.wcfin.ca

Use of distillers by-products in the beef cattle feeding industry
Journal of Animal Science (2008) vol. 86, page 1223
http://jas.fass.org

Feeding corn distiller’s co-products to beef cattle
College of Agriculture & Biological Sciences/South Dakota State University
http://www.distillersgrains.org

Distillers Grains for Beef Cattle
Terry Klopfenstein
http://www.distillersgrains.org

Distillers Grains in Cow-Calf and Stocker Programs
Texas AgriLife Extension Service and Texas AgriLife Research
http://oaes.pss.okstate.edu

Canadian Biofuel Industry: Western Canada Perspective and Opportunities
Alberta Agriculture and Rural Development
http://www1.agric.gov.ab.ca

Ethanol Plant
Pound-Maker
A description of the production of distiller’s grains.
http://www.pound-maker.ca

Using Distillers Grains in Alternative Cow-Calf Production Systems
Iowa Beef Center
http://www.iowabeefcenter.org

Use of distillers by-products in the beef cattle feeding industry
Journal of Animal Science (2008) vol. 86, page 1223
A review on using corn DGS in the mid-western states of the USA
http://jas.fass.org

Effect of dried distillers’ grains from wheat on diet digestibility and performance of feedlot cattle
Canadian Journal of Animal Science (2008) vol. 88, page 659
http://pubs.aic.ca/

Effect of graded levels of wheat-based dried distiller’s grains with solubles on performance and carcass characteristics of feedlot steers
Canadian Journal of Animal Science (2008) vol. 88, page 677
http://pubs.aic.ca

Evaluation of wheat or corn dried distiller’s grains with solubles on performance and carcass characteristics of feedlot steers
Canadian Journal of Animal Science (2010) vol. 90, page 259
http://pubs.aic.ca

Substitution of wheat dried distiller’s grains with solubles for barley grain or barley silage in feedlot cattle diets: intake, digestibility and ruminal fermentation
Journal of Animal Science (2011) vol. 89, page 2491
http://jas.fass.org/

Nutrient excretion and odorant production in manure from cattle fed corn wet distiller’s grains with solubles
Journal of Animal Science (2009) vol.87, page 2977
http://jas.fass.org

Impact of feeding distiller’s grains on nutrient planning for beef cattle systems
University of Nebraska-Lincoln Extension RP 190
http://www.heartlandwq.iastate.edu

Comparison of wheat-based dried distiller’s grains with solubles to barley as an energy source for backgrounding cattle.
Canadian Journal of Animal Science (2008) vol. 88, page 721
http://pubs.aic.ca

Wheat-based dried distiller’s grains supplementation in backgrounding and stocker programs
Western Beef Development Centre
http://www.wbdc.sk.ca

Using distillers grains in alternative cow-calf production systems
Iowa Beef Center
Includes examples of typical rations containing corn DDGS for cows together with cautionary notes on phosphorus and sulfur are dealt with.
http://www.iowabeefcenter.org

 

Feedback

Feedback and questions on the content of this page are welcome. Please e-mail us at info [at] beefresearch [dot] ca.

Acknowledgments

Thanks to Dr. Jock Buchanan-Smith, retired University of Guelph professor and researcher of beef cattle nutrition and management for contributing his time and expertise in writing this page.

This topic was last revised on February 29, 2016 at 09:02 AM.

Fact Sheets

Canadian Cattlemen's Association Verified Beef Production Canada Beef
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