2013 Annual Report
1a.Objectives (from AD-416):
Quantify the impact of reducing oil in DDGS on the ME in growing pigs and poultry.
1b.Approach (from AD-416):
1. Analyze four samples of OE-DDGS (10.5, 7.5, 5.5 and 4.5% oil, as-is basis) for CP, EE, starch, NDF, acid detergent fiber (ADF), total dietary fiber (TDF), ash, and minerals. 2. Conduct energy (DE and ME) digestibility study with pigs fed OE-DDGS. 3. Conduct energy (ME only) digestibility study with broilers fed OE-DDGS.
4. Correlate DE and ME for swine and ME for broilers to OE-DDGS composition.
5. Compare DE and ME to previously determined regression equations and data.
All animal, laboratory, and data analysis for this project have been completed. As expected, as the percent ether extract (EE) in reduced oil-dried distillers dried grains with solubles (RO-DDGS) was reduced, gross energy decreased while total dietary fiber, crude protein, and ash concentrations increased. In contrast, and unexpectedly, neutral detergent fiber appeared to decrease as oil was extracted. Mycotoxin contamination in each RO-DDGS sample was also analyzed, and although some mycotoxins were detected, they were well below limits of concern. Digestibilities of various components in the RO-DDGS differed between treatments, but were not helpful in predicting digestible energy (DE) or metabolizable energy (ME) of the RO-DDGS samples when fed to the pig. This was not expected based upon previous literature, and warrants further evaluation of the data.
The relationship between DE or ME (kcal/kg dry matter) and percent EE in the RO-DDGS (dry matter basis) could be graphed, but the coefficient of determination was poor, being 0.22 and 0.32 for DE and ME, respectively. This lack of relationship can also be denoted by regression analysis demonstrating that the probability value for DE and ME relative to EE content was not significant, being 0.54 and 0.43, respectively. Regardless of analysis for the RO-DDGS samples utilized in this experiment, no combination of nutrient analyses could be used to predict the DE which was obtained in the pig, as has been denoted in our past research. In summary, relating DE and ME to only the percent EE in RO-DDGS was not a statistically sound method of analysis, with the data in the current experiment suggesting that additional parameters such as gross energy and "fiber" are necessary for improved prediction equations.