As ethanol production grows, so does the supply of distillers’ dried grains with solubles. Incorporating DDGS into swine diets remains a source of debate, concern and sometimes confusion. It is, however, gaining attention as producers search for ways to lower feed costs.

There have been several studies to determine the proper DDGS inclusion rates for almost all production phases. However, all the answers are not yet available, and finding a one-size-fits-all recommendation is unlikely. To find the DDGS inclusion rates that work best for your finishing herd, you need to consider performance factors such as growth rates, carcass yield, health effects and mortality. When DDGS is added to sow rations, you must consider reproductive parameters such as litter size and weaning weights.

Always at issue when it comes to DDGS is quality. But processing of this ethanol byproduct has improved as new ethanol plant construction methods have come on line. University of Minnesota studies show that DDGS produced by these newer plants contains higher levels of metabolizable energy, digestible amino acids and available phosphorus when compared to DDGS from older plants. Such factors increase your chances to more effectively incorporate DDGS into lactation-sow diets.

There is limited research investigating DDGS’ effects on sow performance during lactation. However, University of Minnesota research looked at inclusion rates from 15 percent to 30 percent. Among the findings was the fact that sows fed DDGS weaned more pigs per litter during the second reproductive cycle compared to sows receiving corn/soybean meal diets.

When considering DDGS for use in sow diets, the first hurdle is to evaluate the available nutrient content. “DDGS uniformity from batch to batch within the same plant is improving,” says Sam Baidoo, University of Minnesota associate professor of swine nutrition and management. “Nutrient levels in DDGS do not change much, but the nutrient availability for animal use does vary, which can largely be due to the DDGS drying process.”

Nutrient testing is a good idea, but it’s not a necessity for each DDGS batch. “It’s not necessary to regularly test DDGS for protein and lysine before including it in rations,” Baidoo says. “Color is an important indicator of quality.” It can range from a light yellow to very dark brown. He points out that while bright yellow DDGS could have the same crude protein and total lysine levels as dark brown DDGS, the nutrient accessibility and palatability is different. Sows would be better able to utilize the protein and lysine from the bright yellow DDGS than the dark brown version.

The color of grain used and the amount of solubles added in the DDGS production process can influence color. Drying time and temperature during the production process are the factors most likely to affect DDGS color and lysine digestibility. Depending on the plant, dryer temperatures can reach 1150º F.

So, DDGS color may provide your first line of defense; it offers an indication of digestible lysine content, which influences performance results, and that affects the economics of whether to include DDGS in your rations.

With feed costs the red-hot topic of the day, Baidoo suggests examining three main factors to determine the economics of adding DDGS to lactation-sow diets:

1. Price of feed ingredients

2. Cost of substitution

3. Impact on performance.

In a Minnesota Pork Board-sponsored study, University of Minnesota researchers found that including DDGS in lactation-sow diets increased the margin-over-feed cost for diets with 20 percent and 30 percent DDGS levels. The inclusion of 20 percent DDGS increased the margin-over-feed costs by $6.60 per sow.

Follow-up studies have convinced Baidoo that lactating sows receiving a 30 percent (bright yellow) DDGS inclusion rate produced performance similar to lactating sows fed corn/soybean meal control diets. As a result, he has upped his recommended DDGS inclusion rate for both gestation and lactation diets. “At the moment, we will recommend a 30 percent (bright yellow) DDGS inclusion rate,” he says.

Introducing a diet with DDGS does not usually cause feed intake interruptions. “Sows can go straight to DDGS-based diets without any unfavorable reactions,” Baidoo says. That is, provided the DDGS quality is high. “Sows will easily accept the bright yellow DDGS,” he adds.

Formulation is Paramount

You should pay particular attention to the formulation specifications of the DDGS used in sow diets. “It is important that diets containing DDGS be carefully formulated based on concentrations of digestible amino acids and digestible phosphorus,” according to Hans Stein, University of Illinois swine specialist.

He recommends a lysine-to-crude-protein ratio of 2.8 percent or greater.   “Because lysine is usually the first limiting amino acid in swine diets, DDGS with a lysine-to-crude-protein ratio that’s less than 2.8 should not be used,” he says.

Because the protein in DDGS is relatively low in lysine, additional L-lysine should be included. “In lactating-sow diets, the inclusion of crystalline L-lysine should be increased by 0.1 percent for each 10 percent DDGS included in the diet,” Stein says. “At the same time, 4.25 percent soybean meal and 5.7 percent corn can be removed.”

Another factor to note is that phosphorus present in DDGS is more digestible. According to Stein, 0.2 percent monocalcium phosphate can be removed from the diet for each 10 percent DDGS that is included. However, Stein goes on to explain that additional limestone is needed to maintain a proper concentration of calcium.

Then there’s the mycotoxin factor to be aware of as the ethanol production process concentrates molds that originated in the corn by as much as three-fold, and mycotoxins can cause performance problems, especially for sows.

To monitor this, ask to see the plant’s mycotoxin policy and test results. If you suspect the presence of mycotoxins, send a sample of the DDGS product in question to a laboratory for your own analysis and confirmation.

Including DDGS in your sow rations can alleviate some economic pressure. However, the DDGS source, color, quality and inclusion rates require careful selection. Also, pay close attention to the final diet formulation to ensure adequate digestible amino acids.