As you struggle with increased feed costs, a key decision is whether to include distillers’ dried grains with solubles in swine rations. You contemplate, “How much can I pay? What inclusion rate shall I use? What is the economic benefit?”

Duane Reese, University of Nebraska Extension swine specialist, provides answers to these questions and more to help you decide whether or not to start feeding DDGS.

DDGS Economics 101

Because fuel and corn prices fluctuate, estimating the economic benefit of feeding DDGS requires constant evaluation. “This is a fluid subject and it changes rapidly,” Reese admits. “A couple months from now the situation may be much different.”

In a calculation that illustrates basic DDGS economics, Reese offers the example of removing 178 pounds of corn, 19 pounds of soybean meal and 6 pounds of dicalcium phosphate from a ton of finishing feed. He estimates the cost of those ingredients at $13.19.

He then replaces the three ingredients with 200 pounds of DDGS and 3 pounds of limestone to reformulate a sample ton of 10 percent DDGS ration. 

To remain on par with the cost of the original diet, you shouldn’t pay more than $13.19 for the DDGS and limestone used to replace the corn, soybean meal and dicalcium phosphate. In this case, 6.5 cents per pound for the DDGS — or $130 per ton — is the maximum price you can pay to match the original diet’s costs. This example assumes no difference in pig performance due to adding DDGS.

The question many producers ask is, “What is the optimum DDGS inclusion rate that I can use?” To answer this, Reese provides suggested and maximum DDGS inclusion rates by pig growth phase.

Considering Performance Effects

It is true that adding DDGS to rations may impact pig performance. While it is not fully understood why the performance effects occur, it may be possible to factor them into your calculations. Here’s a look at some known performance aspects.

When DDGS is fed at the suggested levels in Table 1, you could expect sows’ reproductive performance to be similar to that delivered by a corn/soybean meal diet with two possible exceptions: 

  • Lactation feed intake may be depressed. This is a possible red flag for using DDGS in lactation-sow diets. The effect, perhaps due to DDGS’ high fiber content, has been noted in first-parity sows during early lactation only. However, you may be able to minimize this effect by introducing DDGS into the diet about five days before a sow is scheduled to farrow versus right at farrowing.
  • Litter size may increase. During the second reproductive cycle, an improvement in the number of pigs weaned per litter was noted with DDGS in the diet. “This is not totally unexpected, as previous research on added fiber to gestation-sow diets shows a slight improvement in litter size,” Reese notes.

Grow/finish diets account for the largest DDGS use, and, therefore, it’s important to be aware of the possible effects you may encounter. If you use 10 percent DDGS in your grow/finish diets, you can expect similar performance as that delivered by a corn/soybean meal diet.

The exception is a slight decrease in carcass yield, an effect that is not fully understood but again may be due to fiber content. Reese points to five studies that looked at DDGS’ effect on carcass yield. The studies showed that as DDGS rates increased, a corresponding decline in carcass weight occurred.

So, before you can make an accurate economic assessment of DDGS, you should figure in the impact of slightly lower carcass yields. Reese compares the margin-over-feed cost of a diet containing 10 percent DDGS to one with no DDGS.

In the previous economics example, which did not consider performance effects, with $3.20-per-bushel corn prices you could pay $130 per ton for DDGS and come out even. Now, to offset the lost revenue due to reduced carcass yield, the DDGS price would need to drop to $106.35 per ton.

There has been little research on the health benefits of adding DDGS to swine diets, Reese notes. One study that looked at DDGS fed to pigs challenged with Lawsonia intracellularis, an organism often associated with ileitis, showed that DDGS did not reduce the disease incidence or severity. Of course, more research is needed.

Perhaps most interesting is a study that showed a decline in pig mortality as DDGS inclusion rates increased up to 30 percent. “While I don’t think producers can count on lower mortality due to DDGS in the feed, one can speculate its addition may affect the microflora in the intestinal tract,” he adds. However, due to the lack of data supporting a link between feeding DDGS and improved pig health, Reese cautions against assigning a premium to this prospect.

Proceed with Caution

Among the other concerns still surrounding the use of DDGS in swine diets is protein quality. “Protein found in DDGS is corn protein, which has relatively poor value for pigs compared to the protein found in soybean meal; it lacks lysine as well as other essential amino acids,” Reese notes.

For nutrients such as protein, fat, lysine and phosphorus, there is no question that DDGS quality varies widely between plants and even by batch. Try to get a nutrient analysis from the plant before you purchase DDGS or have it done yourself. “Look for 0.78 percent or higher lysine and 10 percent or higher total fat,” he says. “There is much variability in products currently available, and until we get a better handle on how to manage this, I don’t think usage will increase a lot.”

Mycotoxins are another issue that you can’t dismiss. If mycotoxins are present in the corn, the ethanol production process concentrates those levels in the final DDGS product. “It’s something producers need to watch,” Reese says. Again, this means asking for test results or having product tested.

There are other practical issues worth considering before you buy DDGS. Among those are how to transport, handle and store the product. For example, a storage bin that holds 8 tons of a corn/soybean meal diet holds only 7.8 tons of 10 percent DDGS diet because of its higher bulk density. So, you will need more capacity, as well as possible equipment adjustments.

Feeding DDGS can improve your bottom line, but there are hazards that you may face along the way. Don’t let them trip you up — do your own research.

Getting the right rate

“If you haven’t yet tried adding DDGS to swine diets, try adding it near the levels within the ‘suggested’ column,” says Duane Reese, University of Nebraska Extension swine specialist. “There is a good amount of data that predict pig response at these levels.”

The maximum levels shown here are based on what swine nutritionists understand about DDGS products and performance, as of today.

Table 1:

Suggested and Maximum DDGS Inclusion Rates (percent of diet)

Growth Phase






(>25 lbs.)
























Source: Duane Reese, University of Nebraska

As DDGS rises, carcass yield declines

For each 1 percent of DDGS added to the finishing diet, carcass yield declines by 0.04 percentage units on average. Therefore, if a corn/soybean meal diet produces a 200-pound carcass, a pig fed a 10 percent DDGS diet to slaughter weight would yield a 199-pound carcass.

“However, new research suggests that by withdrawing the DDGS six weeks before slaughter, it’s possible to avoid the carcass yield decline,” Reese points out. 

Table 2:

Carcass Yield Effects from DDGS Inclusion

DDGS inclusion rate


Carcass weight






200 lbs.






199 lbs.


-1 lbs.




198 lbs.


-2 lbs.



197 lbs.


-3 lbs.

Source: Duane Reese, University of Nebraska

Measuring the margin

After incorporating the effect of a slight reduction in carcass yield, Reese considers the margin-over-feed cost delivered by rations with and without DDGS at various corn prices. The far-right column shows the price that you can pay for DDGS and still maintain margin-over-feed similar to corn/soybean meal rations at various corn prices.

Table 3:

Margin-over-Feed Cost After Yield Effect

Corn price (per bushel)


Without DDGS

(dollars per pig)


(dollars per pig)

DDGS price to equal MOF (price per ton)


















































Source: Duane Reese, University of Nebraska