You are here

Hogs dig DDGs

With the enormous expansion in Midwest ethanol production, hog producers in the region would be remiss if they didn't examine the use of dried distillers grain (DDG) in their feed rations.

Sometimes they can save a little money with DDGs, sometimes they can save a lot.

DDG swine rations appear to be a success story within both the hog industry and the ethanol industry. And corn farmers would be remiss too if they didn't sit up and take notice, as the more DDGs that hog farmers buy, the less whole corn (and soymeal) they need.

Some hog producers are very familiar with DDGs, while others are not. But even the veterans should keep up with co-product trends that are taking place, because it's not a static industry.

Ethanol In Transition

One Midwest corn miller says it's an industry "in transition," with the possibility of a different menu of feed products -- and different pricing -- within the next five to ten years.

It's called "fractionation," or the process of selling the corn kernel off in smaller and smaller pieces. And livestock producers, as well as corn farmers, can expect to hear a lot more about it. In fact, a new research center on the topic just opened last fall at Southern Illinois University. But current research claims that fractionation added 15 cents a bushel to the 2009 corn crop. So you can expect processors to do more of it.

For hog farmers, fractionation is already a concern because some ethanol plants are removing the high-energy corn oil from DDGs. There's even the possibility that the DDG solubles may be sold separately.

DDG Buyer Beware


Table courtesy University of Illinois.

While the industry talks of dried distillers grain, most of what's currently sold is DDG with solubles, called DDGS. That's what most of the hog-nutrition research is based on. Solubles are dissolvable nutrients in the water when corn is fermented for ethanol. After fermentation (which removes the corn starch), the liquid is wrung out of the remaining undissolved grain. That dried undissolved grain is called DDG.

At the same time, the liquid is dried, yielding "soluble" nutrients that are added back to the DDG. The solubles are rich in protein and energy for the hogs, and must be part of the ration. Since plants can sell their solubles separately, hog producers need to make sure they are getting solubles with their DDG.

Currently underway at some plants is the removal of corn oil from DDGS. In fact, farmers who feed DDGS have started to classify ethanol plants as "high-fat" or "low-fat," depending on how much oil is in the DDGS. A high-fat plant may sell DDGS with as much as 10-12 percent oil, but University of Illinois nutrition researcher Hans Stein has seen levels as low as 4 to 6 percent. (He also reports that some DDGS is de-oiled.)

Through fractionation, even protein levels can vary widely, and the feed buyer needs to know what he's getting from each plant. "Despite a lot of progress in the ethanol industry to produce a consistent (DDG) product, there's still quite a bit of variability for some nutrients," says northern Iowa hog producer Leon Sheets. "You can't buy DDGS based solely on price -- you have to look at the nutrient value that each plant is supplying," says Sheets, who has used DDGS for about 10 years.

DDG Feed Smells Sweet

Oil content is one of those variabilities. But several years ago, before the ethanol industry worked with hog producers to produce a more usable DDG, the problem was not oil but lysine, an amino acid that's key to hog growth. Early DDGs were not palatable to hogs, so very little was used by farmers. Unpalatability was largely linked to the undigestability of the lysine in the DDG. And the culprit was overheating during the drying process. It was found that less heat makes lysine more digestible, and the ethanol industry has worked to avoid overheating. Researchers say that some overheated DDGS can still be found, so farmers need to inspect their supplies. DDGS for hog consumption should be golden. Brownish suggests overheating. The DDGS should smell sweet and fermented, not burnt.

Because lysine is so important, Dr. Stein advises farmers to buy DDGS only when the lysine content is at least 2.8 percent of crude protein. For example, if the crude protein is 30 percent, buy only if the lysine content is at least 0.84 percent. 

Notably, while heating hurts the lysine, it apparently makes the phosphorus in corn more digestible to hogs. One of the major cost savings of using DDGS comes from cutting back on supplemental phosphorus in the ration.

Saving with DDDGs


Table courtesy University of Illinois.

Cost savings also come from replacing some of the corn and soymeal in the ration. As a general rule, says Stein, each 10 percent of DDGS in the ration can eliminate 5.5 percent corn and 4.5 percent soymeal.

His research has found savings of up to $5-$10 per hog, but other farmers have reaped smaller savings, depending on pricing and ingredient substitution rates. For example, Illinois hog producer Mike Haag was enjoying savings of $3-$4 per hog, but that slipped to about $1 last fall when corn prices slumped after harvest. He notes that DDGS prices do not seem to fall as fast as corn prices.

While ingredients like corn, meal and phosphorus can be cut back, other supplements may have to be added, such as lysine, tryptophan and fat (depending on the oil in the DDGS).

How Much To Feed

The overriding factor when using DDGS is that it's corn with the starch removed. Since starch is about two-thirds of the corn kernel, the ingredients left in the DDGs are about three times more concentrated than they are in a corn kernel. So there's three times as much protein (allowing DDGS to replace soybean meal) and there's three times as much oil (if the processors haven't skimmed some off).

There's also about three times as much fiber, which can create digestibility problems for hogs.  And if there is any mold or other toxins in the corn, then those become three times as concentrated in DDGS. For that reason, Sheets feeds only about 15 percent DDGS to his gestating sows, when research allows as much as 50 percent. His lactating sows get virtually no DDGS, as toxins would show up readily in the milk.

Similarly worried about toxins, Haag feeds no DDGS to his sows. He hasn't found much economic benefit. Some university researchers suggest that DDGS in breeding-herd diets may increase litter size, but there's little conclusive data.

Fractionation Worries

Meanwhile, Haag is concerned about fractionation. He estimates that removal of the oil is devaluing the DDGS by about $20-$25 per ton.

But fractionation isn't necessarily all bad for livestock producers -- if it lets them pick and choose from the nutrients they need. And in hogs, reduced corn-oil content in DDGS can improve the quality of the meat (but reduced oil extends length on feed due to lower energy content).

A major concern with DDGS-fed hogs is that the corn oil makes the carcass soft, especially the high-value pork belly. But reduced-oil DDGS has led some hog producers to boost their DDGS to 30-40 percent of rations, when 20 percent is the norm (and about 10 percent 15-20 years ago). The higher DDGS rates allows them to save $5-$10 per hog, instead of $2-$3.

Corn oil is high in lineolic acid and other unsaturated fats that are liquid at room temperature, and high-oil DDGS is about 10-12 percent oil. Some plants have started to impose discounts for soft-fat carcasses from DDG-fed hogs, and that offsets the feed-cost savings. Soft fat is especially a problem in some export markets, such as Japan, which prefers a firm fat, says University of Minnesota researcher Jerry Shurson.


Table courtesy University of Illinois.

He says there are three common ways firm up the fat before slaughter:

Ramp up, ramp down. Start pigs off with about 20 percent DDGS when they are around 60 pounds. (Many farmers start around 25 pounds, or about two weeks after weaning.) To achieve cost savings, ramp up to about 30-40 percent DDGS until the hogs weigh about 200 pounds. Then ramp down the DDGS rate to 10-20 percent by the time the hogs are 260-280 pounds.

Flatter rations. Starting at about 60 pounds, feed the pigs 30 percent DDGS until the last three weeks before slaughter. Then transition down to about 0 percent.

Compute an "iodine value" (IV) for each feed ingredient. The IV gives an indication of the amount of unsaturated fat in each component. Plug each individual IV into a formula to compute an IV for the entire ration. The lower the IV of the feed, the firmer the pork fat, says Shurson.

Editor's Note: Andre Stephenson serves as a freelancer for Successful Farming/

Read more about

Talk in Marketing

Most Recent Poll

Will you plant more corn or soybeans next year?