Pork carcass “doesn’t change very much” when distillers dried grains with solubles (DDGS) is fed, said Dr. Gerry Shurson, a University of Minnesota animal scientist. DDGS “is a good alternative ingredient and significantly reduces feed cost,” he said at the Allen D. Leman Swine Conference in St. Paul, Minn.

Up to 30% of DDGS “fits nicely” into all phases of swine production. “The reason why it hasn’t been used up to those levels is that it’s a confidence factor. For many people, it’s a fairly new ingredient. They may not know very much about it or what some of the limitations are, or how to formulate the diets corrected based on what the nutrient variability can be among sources.”

He said that as producers we get more confidence and information about DDGS, increased amounts of it will be used.
The biggest question, he said, is how much can be used without compromising pork fat quality. DDGS contains about 10% corn oil and that corn oil is highly unsaturated so it tends to make pork fat more soft or oily as we feed very high levels and that becomes a concern for being competitive in the marketplace.

“If you’re a pork processor, that’s one of the questions being asked right now in the industry,” he said.

Iodine value
 The iodine value is currently the single criterion that’s being targeted on pork fat quality. Iodine is the ratio of saturated and unsaturated fats.

“Pigs are what they eat, so if we feed diets that are high in unsaturated fats like corn oil from distillers grains, it will make the pork fat more soft or oily, especially at high levels. If we take it out of the diet at some point before harvest, pork fat becomes firmer again, assuming we revert back to more saturated fats in the diet, or simply corn/soy-based diets. So by manipulating the fatty acid profile in the diet, it allows us to manage the iodine or softness of pork fat as a result. That’s something fairly easy to manage.”

More DDGS could be fed to sows, in Shurson’s view.

“The concern has been the perception of high mycotoxins. But the prevalence of mycotoxins is much lower than most people expect. I think people are remembering back in the old days, when bad quality corn, maybe mold and mycotoxin-contaminated corn was being used to produce ethanol, whereas today there is the incentive to use only the best-quality corn to maximize ethanol yield. So we don’t really have much of an issue. As producers become more aware and more confident in the low risk of mycotoxins I think we’re going to see more use of DDGS in sow diets.”