March 22, 2012

US study affirms safety of DDGS in swine feeds

Swine producers can feed distiller's dried grain with soluble (DDGS) to their pigs without concern for sulphur content as reported by the University of Illinois research.

"When you buy DDGS, you don't have to be concerned about the level of sulphur it contains because there doesn't appear to be any impact on pig performance," says U of I animal sciences professor Hans Stein.

DDGS is a co-product of the ethanol industry that is being used at increasingly higher levels as a feed ingredient in swine diets.

To maintain a stable pH in fermentation vats, ethanol producers use sulphuric acid, which results in a sulphur content in the DDGS that varies according to how much sulphuric acid was used. Until now, the effect of low levels of sulphur in the diet on growth performance in pigs fed DDGS had not been determined, Stein explains.

"Sulphur is toxic to cattle. If there is 0.4% sulphur in the diet, cattle start getting sick," Stein says. "Because there hasn't been any work on sulphur toxicity with swine, we wanted to determine how sulphur affects palatability and performance in pigs."

In a recent study, Stein's research team compared a low-sulphur (0.3% sulphur) DDGS diet with a high-sulphur (0.9% sulphur) DDGS diet. The same DDGS was used in both groups. The researchers compared palatability and growth performance of the pigs fed the low-sulphur and high-sulphur diets.

"We conducted four experiments: two with weanling pigs and two with grow-finish pigs," Stein says. "In both weanling pigs and grow-finish pigs, there was absolutely no difference between the two. The levels of sulphur we used in our experiments had no impact on palatability or pig growth performance."

Stein says that the results of this research would be useful to producers interested in incorporating DDGS into swine diets, but further research is needed to determine whether excess sulphur from a high-sulphur DDGS diet is deposited into swine tissues.