Pork producers looking to optimize feed ingredients are including distiller's dried grains with solubles (DDGS) for grow-finish pigs when costs are in line.

To better understand the implications of suddenly including economically priced DDGS in pig diets, researchers at the University of Minnesota conducted a trial to determine the effects of switching between corn-soybean meal and corn-soybean meal-DDGS diets on pig performance and carcass quality of finishing pigs.

The 216 pigs housed in 24 pens were placed on one of four dietary treatments — the corn-soybean control diet (D0), a corn-soybean meal diet containing 20% DDGS fed throughout the study (D20), D20 and D0 diets alternated bi-weekly (D20SW), and a 40% DDGS diet alternated bi-weekly with the D0 diet (D40SW). Pigs were fed corn-soybean meal diets until they went on test at 110 lb.

There were five, two-week feeding periods. Pigs assigned to the D20SW and D40SW treatments started and ended the trial on DDGS-containing diets.

Dietary treatments had no effect on average daily gain (Table 1). Except for feed efficiency, growth performance was similar for pigs fed the control diet continuously, the 20% DDGS diet continuously or the 20% DDGS and control diets in an alternating pattern.

Researchers point out that for some reason, pigs fed the 20% DDGS diet were continuously less efficient than pigs fed the DDGS diet alternated with the control diet.

They also noted that the pigs switched on and off a 40% DDGS diet were lighter at the end of the 70-day study (Table 1), and these pigs yielded lighter carcasses than pigs in other treatment groups because they ate less feed.

Dressing percentage and carcass fat-free lean percentage were not affected by dietary treatments.

The results of this study showed no adverse effects of frequently alternating between inclusion and removal of 20% DDGS from diets for finishing pigs in terms of performance or carcass characteristics.

The researchers plan to conduct a related trial to determine if lighter pigs will respond in the same manner.

Researchers: Lee Johnston and Adrienne Hilbrands, University of Minnesota, West Central Research and Outreach Center; and Jerry Shurson, University of Minnesota-St. Paul. Contact Johnston by phone (320) 589-1711, fax (320) 589-4870 or e-mail johnstlj@morris.umn.edu.