It appears there are as many questions as answers about distiller's grains in hog rations.

Gregg Sample summed it up best at the “Distiller's Grains: Implications for the U.S. Pork Industry” meeting hosted by the Pork Checkoff in Des Moines, IA, in late November.

“It is a hot topic and there are a lot of opinions,” said Sample, director of nutrition and information at Next Generation Pork (NGP), LeRoy, MN. For the past four years, NGP has been feeding dried distiller's grains with solubles (DDGS) as 10-15% of finishing rations on a least-cost basis. Still, Sample admitted he has a lot to learn about the feedstuff.

After a day of listening to economists, ethanol marketers, researchers, feed industry experts and animal scientists, it is safe to say that many in the pork industry are in the same boat as Sample.

Questions about economics, nutrient content and digestibility, optimum feeding levels and performance results related to feeding DDGS in swine rations prevail.

Shifting Demand for Corn

One thing is crystal clear — the Corn Belt is experiencing a “run up” in ethanol production, which is already having an impact on livestock producers.

Bill Holbrook, a grain market analyst with ProExporter Network, said the demand for corn for ethanol production could match the demand in the U.S. feed industry within the next 10 years. He estimated more than 13 billion gallons of ethanol will be produced annually at current plants and those that will be expanded or come on line in the near future. That equates to five billion bushels of corn used for the renewable fuels industry.

“This is something we haven't seen before within the industry on a sustainable basis,” said Holbrook. He anticipates more volatility in corn markets and continued downward pressure on DDGS prices until the livestock industry develops a better understanding of how to use the feedstuff. “It is going to be a little bit wilder ride than we've had in the past,” he added.

Steve Meyer, president of Paragon Economics, Inc., Des Moines, characterized the burgeoning ethanol industry as “the greatest change in American agriculture since the tractor.” Meyer is concerned about the consequences of higher priced corn — especially for hog producers.

“We've added $5-6/cwt. to the cost of production,” based on $30-40/ton feed cost increases during the fall of 2006, he reminded.

Meyer said ethanol subsidies and high fuel prices would keep ethanol manufacturers in a highly competitive buying position. “Modern ethanol plants can pay somewhere around $4/bu. for corn,” he said.

In addition, the ethanol boom has shifted the competitive environment among livestock producers. Today, DDGS is not nearly as useful as a feedstuff for hogs or broilers as it is for cattle. DDGS is about $20/ton higher in value in dairy diets compared to swine diets, and about $12/ton higher in value for beef cattle.

Apples and Oranges

One of the growing pains associated with DDGS is the lack of agreement on standardized testing for nutrient content analysis, according to Richard Sellers, vice president of feed regulation and nutrition in the American Feed Industry Association (AFIA). “There are a lot of different analytical methodologies out there and you can't be trading these products based on apples and oranges,” said Sellers.

Last year the AFIA created a working group of suppliers and users of DDGS to review the issue. They found a great deal of variation in sampling methods and how feed samples are tested for moisture, crude protein, fat and fiber.

The working group supported a two-part study, sponsored by AFIA, the National Corn Growers Association and the Renewable Fuels Association, to be completed early this year. The first phase looked at efficacy and applicability of the various nutrient content testing methods used, and also attempted to shed light on how much variation occurs within a single laboratory. The second phase was designed to quantify the precision of the respective testing methods across several laboratories.

Another organization attempting to answer questions about ethanol-related issues is the National Corn-to-Ethanol Research Center in Edwardsville, IL. Director John Caupert explained the center's research on how to produce ethanol more efficiently. Recent projects have studied coproduct variability, including flowability and presence of mycotoxins, and ways production practices can affect coproduct components, such as moisture, other nutrients and physical attributes such as color.

The facility has a waiting list for new projects. In addition to research, the center offers workforce development and education for those employed or wanting to work in the ethanol industry.

What Suppliers Say

Sean Broderick of Commodity Specialists said a lot of work must be done to improve flowability and handling of DDGS, and to understand nutrient composition, such as whether color indicates true nutrient quality.

Broderick noted the strongest economic incentive ethanol producers face is to increase throughput. Improving the quality of coproducts is a lower priority, because DDGS reflects only 10-15% of economic returns to ethanol plants. When ethanol is produced faster, “variability is greater,” he added.

Randy Ives of U.S. Bioenergy agreed that improving flowability of DDGS is a high priority for ethanol distillers. Controlling sulfur and phosphorus plus providing consistent nutritional values is also important.

Ives recommended that pork producers build strong relationships with the plant supplying their distiller's grains. “Be plant specific,” he said. “You have to know what they are doing and what their philosophy is, day in and day out.”

Brian Knudson of Cargill urged pork producers and nutritionists to focus on nutrients such as energy, carbohydrates and protein, or more specifically digestible amino acids such as lysine, rather than simply focusing on ingredients (DDGS, soybean meal).

David Russell, vice president of product development and technology for Renessen, LLC, discussed a new processing technology at a pilot plant in Eddyville, IA, where Renessen's Mavera nutrient-dense corn will be processed into corn oil, a highly fermentable starch fraction for ethanol and a nutrient-rich swine feed that can replace corn in the swine diet.

This swine feed will allow for a reduction in soybean meal, eliminate the need for synthetic lysine and reduce feed-grade phosphorus. The low-oil, low-moisture feed also promises to improve flowability and handling in feedmills, compared to traditional DDGS. It is expected to be marketed beginning in 2009.

Renessen, LLC is a joint venture between Cargill and Monsanto.

Economic Impact

Iowa State University agricultural economist John Lawrence said pork producers would react to higher feed prices by marketing hogs at lighter weights. “Slaughter weights will be lower in the future than they have been in a $2.00 corn world,” he said. “The change won't be large, but 5-lb. lighter average weights are not out of the question. That's difficult for most of us to fathom because we've been in this mode of more pounds, more pounds, more pounds.”

The impact of lighter hogs on income will depend on each producer's situation, said Lawrence. Producers accustomed to selling hogs above the packer's highest premium weight range may not suffer because they will sell fewer pounds of pork but at higher prices.

In contrast, producers who are constrained by space and currently sell hogs below the premium weight in a packer grid will sell less weight for less money. “His return will drop off much quicker,” said Lawrence.

Citing performance data developed by Mark Whitney and his colleagues at the University of Minnesota for grow-finish pigs on 0, 10, 20 and 30% DDGS diets, Lawrence noted pigs on diets with 10% DDGS showed no difference in performance (vs. pigs fed no DDGS). The conclusion: DDGS at the 10% level is useful if it lowers feed costs.

However, with 20% and 30% DDGS diets, average daily gain, feed conversion and dressing percentages drop off. For example, for pigs on 30% DDGS diets, Lawrence calculated a $2.41/head difference in return over feed costs vs. pigs fed no DDGS. In other words, the 30% DDGS diet must save at least $2.41/head to be beneficial.

In addition to considering the impact of current corn prices and lower market weights, Lawrence cautioned producers to be on the lookout for other factors, such as carcass quality or packer premium changes, or shifts in DDGS content, quality and price.

Digestibility of Nutrients

University of Illinois associate professor of animal science Hans H. Stein reported on his research to illustrate the great deal of variation in nutrient digestibility of DDGS samples, particularly in lysine.

Stein measured 36 samples of DDGS for nutrient content. He found crude protein concentration levels ranging from 24 to 30% and lysine concentrations ranging from 0.54 to 0.99% (see Table 1).

But nutrient concentration is only part of the story, because poor digestibility can cause even greater variability in the nutrient value of a feedstuff. In further testing, Stein found that pigs could only digest 44 to 78% of the lysine available in the DDGS sampled (see Table 2).

“The samples that had the lowest lysine concentrations tended to have the lowest digestibility,” said Stein.

Knowing producers can't go out and measure lysine digestibility, Stein recommended having DDGS samples tested for nutrient content, then dividing lysine concentration by crude protein concentration to estimate a lysine digestibility. In Stein's studies, an average sample calculated to 2.86 lysine/crude protein %.

At 2.86 or higher, “you have a decent product,” said Stein. “The higher the number the better.” For anything lower than 2.8, Stein recommends producers either reject the batch of DDGS or negotiate to purchase it at a lower price.

Stein gave many reasons for the variability, including corn variety, the amount of solubles added back to DDGS, drying temperature, duration of processing and incomplete fermentation.

Sow Performance with DDGS

University of Minnesota animal scientist Jerry Shurson gave three informal observations from producers about the effect of feeding DDGS in sow diets:

  • Increase in lactation feed intake.

  • Sows are more content.

  • Sows may experience fewer constipation problems.

Shurson also provided background on three formal research trials:

A University of Minnesota study suggested that DDGS may have an effect on litter size. During the second reproductive cycle, researchers saw a tendency for an increase in litter size (almost a pig/litter) for sows fed DDGS diets during gestation or lactation or both, when compared to corn-soybean diets.

However, it is not known whether this increase in litter size response is repeatable, or if it can be achieved only by feeding diets the same as the treatment diet, which contained 50% DDGS in gestation and 20% DDGS in lactation.

The study also suggested that sows could experience a setback in feed intake if they went from corn-soybean meal diets during gestation to a DDGS diet during lactation.

At Michigan State University (MSU), a study looked at the effect of 15% DDGS on reducing sow performance and phosphorus excretion in manure, compared to sows on 5% beet pulp diets.

MSU researchers saw no significant differences in sow weight gain, litter weight, litter weight gain and number of pigs weaned between the two dietary groups. They saw decreases in manure phosphorus concentration in pigs on DDGS diets. However, Shurson noted, with a high fiber content in DDGS feeds, manure output may actually increase, so total phosphorus excretion may not be reduced significantly.

This trial concluded that adding 15% DDGS in sow lactation diets supports lactation performance and may reduce fecal phosphorus excretion.

Another University of Minnesota (unpublished) study compared feeding various levels of DDGS in lactation diets vs. a corn-soybean meal control diet. The study measured sow and litter performance; energy and nitrogen balance in sows; blood urea nitrogen; milk fat and protein content; and economics between diets, including 0, 10, 20, 30% DDGS and a 30% high-protein diet containing DDGS.

Sow and litter performance were not affected by feeding sows up to 30% DDGS in lactation diets. In addition, there was no difference in nitrogen uptake or nitrogen retention for sows on the DDGS diets (any level) and control diets without DDGS. Furthermore, there was no difference in nitrogen or fat content in milk between the control and DDGS diets. Blood urea nitrogen was lower for sows fed the 20 and 30% DDGS diets vs. the corn-soybean diets and 30% DDGS high-protein diets.

Nursery Pig Performance

Extension swine specialist Mark Whitney described two University of Minnesota experiments measuring the effect of increased DDGS levels (5, 10, 15, 20, 25% vs. control with no DDGS) on nursery pigs.

In both studies, pigs were fed in three stages (by age). Phase 1 (up to 4 days postweaning) consisted of a commercial pellet without DDGS. Phase 2 (fed for 14 days) and Phase 3 (fed for 21 days) consisted of meal diets with DDGS at levels indicated above, plus control diets without DDGS. The first study showed no effect on growth rate, feed intake, feed efficiency and final nursery weight between the control and any of the DDGS diets.

In the second study, a decrease in growth rate and feed intake was noted for pigs on DDGS diets during Phase 2, but no change in feed efficiency was noted. There were no changes in average daily gain, average daily feed intake or feed efficiency for any of the diets in Phase 3.

The DDGS diets had no effect on final nursery weight. Whitney concluded that diets with 5% or more DDGS during Phase 2 may cause decreases in feed intake and growth, but pigs can be fed up to 25% DDGS in Phase 3.

Grow-Finish Performance

Kansas State University (KSU) Ex-tension swine specialist Joel DeRouchey reported that while some research trials indicate that 10 to 15% DDGS in grow-finish diets may or may not decrease growth rate, research has consistently shown that levels of 20% or more have lowered performance.

Ranges of 3-5% reduction in average daily gains were seen in recent trials at KSU, University of Minnesota, University of Missouri and at The Hanor Company. Reductions in carcass yield have also been reported when pigs were fed any level of DDGS.

DeRouchey recommended feeding no more than 10% DDGS in grow-finish rations at the start, then watching results over time. “Producers should closely monitor any performance changes and make adjustments to inclusion levels as needed,” said DeRouchey. “You need to monitor your closeouts and whether there are any changes in carcass data.”

Feeding distiller's grains is also known to increase iodine levels in carcasses due to unsaturated fats in the corn oil in DDGS. DeRouchey said limited research data currently exists, but feeding recommendations to address this concern under normal commercial conditions should be available in 2007.

DeRouchey also urged producers to choose carefully when purchasing distiller's grains, because quality varies from plant to plant and within a plant, over time. “When using distiller's grains, understand the quality of product you are purchasing to determine the economics of its use.”

For More Information

Speaker notes from the conference are available at www.porkboard.org. A video presentation will also be posted online, according to National Pork Board officials.

The meeting was sponsored by the Iowa Pork Producers Association, National Pork Producers Council, Renewable Fuels Association, Monsanto, Iowa Corn Promotion Board, National Corn Growers Association and Iowa Agribusiness Export Partnership.

Table 1. Composition of Samples
Item Avg. Range
Crude protein, % 27.20 24.1-30.1
Ether extract, % 10.20 8.60-12.6
GE, kcal/kg DM 5,429 5,272-5,588
Starch, % 7.27 3.8-11.4
Phosphorus, % 0.71 0.51-0.78
Lysine, % 0.78 0.54-0.99
Acid detergent fiber, % 9.86 7.2-17.3
GE=gross energy; DM=dry matter
Table 2. Percent of Amino Acids in 36 samples of DDGS
Item Range Avg. NRC NRC*
Lysine, % 44-78 63 59
Methionine, % 74-89 82 75
Cysteine, % 66-81 73 60
Threonine, % 62-83 71 65
Tryptophan, % 54-80 69
Isoleucine, % 67-83 76 79
Valine, % 66-82 756 67
*National Research Council
SID=Standardized Ileal Digestibility