The periodic rapid addition or removal of distiller’s dried grains with solubles (DDGS) in grow-finish diets can help reduce overall feed costs.

There is a tremendous economic advantage to feeding high levels of DDGS (40-50%) to pigs, but little data has been accumulated on its impact on pig performance and carcass quality.

However, due to fluctuations in DDGS pricing and availability, it may only be economically feasible to include DDGS in diets periodically throughout the grow-finish phase. The pig’s response to rapid fluctuations in dietary DDGS content has not been documented.

Ethanol plants produce DDGS of varying nutrient content and amino acid digestibility due to differences in processing and drying procedures. If producers were able to rapidly introduce and withdraw DDGS of differing amino acid digestibilities, they would be more likely to include DDGS at high levels in grow-finish diets.

Therefore, the research groups at the University of Minnesota conducted an experiment to determine whether high levels of DDGS of differing amino acid digestibility can be fed continuously or intermittently throughout grow-finish without affecting overall growth performance and carcass quality.

A total of 324 crossbred pigs, housed in 36 pens, were placed on test at an environmentally controlled finishing barn at an average weight of 73 lb.

Each pen was randomly assigned to one of six dietary treatments consisting of a corn-soybean control (CON); CON plus 40% low amino acid digestible DDGS (Lo); CON plus 40% high amino acid digestible DDGS (Hi); and diets alternating between Lo and CON (Lo-CON); Hi and CON (Hi-CON); or Hi and Lo (Hi-Lo).

Feed switches for Lo-CON, Hi-CON and Hi-Lo were made at phase changes at an average pen weight of 111 lb., 151 lb. and 201 lb.

Growth performance and carcass quality of pigs switching between a corn-soybean meal diet and a DDGS diet, regardless of the amino acid digestibility of the DDGS (Lo-CON and Hi-CON), were similar to pigs continuously consuming a corn-soybean meal diet (Table 1).

However, the continuous feeding of a diet containing 40% DDGS with low digestible amino acid content reduced average daily gain, average daily feed intake and dressing percent vs. pigs continuously consuming a corn-soybean meal diet.

It appears that the use of DDGS with highly digestible amino acid content diminished some of the negative effects of continuously feeding DDGS.

Dietary changes also affected average daily feed intake. The switch from a corn-soybean meal diet to a 40% DDGS-based diet caused a reduction in feed intake. But pigs compensated for this depression during the remaining feeding period, producing feed intakes and gains similar to pigs continuously or intermittently consuming a corn-soybean meal diet.

Research results confirmed previous studies indicating that amino acid digestibility of DDGS, or overestimation of digestible amino acid content, can influence pig performance.

More importantly, University of Minnesota results suggest there may be temporary depressions in feed intake of pigs when switched abruptly from a corn-soybean meal diet to a diet containing 40% DDGS. However, over the entire feeding period, growth performance does not appear to be negatively affected if pigs alternate between corn-soybean meal diets and diets with high levels of DDGS.

Researchers: A.M. Hilbrands and L.J. Johnston of the University of Minnesota West Central Research and Outreach Center at Morris, G.C. Shurson and L.W.O. Souza of the University of Minnesota at St. Paul, and S.K. Baidoo of the University of Minnesota Southern Research and Outreach Center at Waseca. For more information, contact Hilbrands by phone (320) 589-1711, fax (320) 589-4870 or e-mail hilbraam@morris.umn.edu.