#08-093

Complete

Date Full Report Received

01/31/2010

Date Abstract Report Received

01/31/2010

Investigation

Institution:
Primary Investigator:

The study has provided a comprehensive investigation on whether or not increasing concentrations of sulfur in distillers dried grains with solubles (DDGS) can impact the palatability and performance of weanling and growing-finishing pigs. The study also has provided in-depth information on various chemical forms of sulfur in DDGS and the cause for increasing sulfur levels in DDGS.

While the majority of production experiments have confirmed that 20 to 30% DDGS in diets fed to growing pigs has resulted in no detrimental effects on performance, some reports have shown reduced feed intake, and thus, reduced pig performance with DDGS included in the diets. To find out if the sulfur in DDGS is the culprit for reduced palatability and performance, we performed feed preference experiments and feed performance experiments with weanling pigs and growing barrows. In both experiments, the pigs fed the control diet (corn and soybean meal) gained more weight and had greater feed efficiency compared with those fed diets containing DDGS. However, there were no differences in performance between pigs fed a diet containing low or high levels of sulfur and it is, therefore, unlikely that the sulfur in DDGS is reducing the palatability of the diet. Producers, therefore, do not need to worry about the levels of sulfur in DDGS because pigs do not reduce performance when fed diets containing DDGS with a high sulfur level compared with pigs fed a diet containing DDGS with a low sulfur level.
Results of the experiment also indicated that the intrinsic sulfur in DDGS, around 0.2 % (wt/wt, as received basis), is contributed from the organic sulfur, mainly cysteine and methionine in corn. However, the major source of sulfur in DDGS is the inorganic sulfur or sulfate and that originates from sulfur that is added during production of ethanol. The inorganic sulfur level in DDGS can vary from almost zero to 0.8 % or higher. The corn to ethanol production process is the main factor responsible for the relatively high sulfur levels in some sources of DDGS.
Based on the results of this experiment, the level of sulfur that are commonly present in DDGS is not a concern for swine palatability and performance with 20 to 30 % DDGS included in the diets. Additional research is currently being conducted to investigate the impact of sulfur in DDGS on tissue levels of sulfur in pigs.