Corn Oil AME and Fat Digestibility

Background Limited research has suggested oils with lower free-fatty acid (FFA) concentrations have a greater energy value than oils with higher levels of FFA. However, there appears to be species differences for this relationship. Energy values in swine were more correlated to FFA than were energy values in poultry. Objective As a result, the objective of this research was to further characterize the apparent metabolizable energy (AME) values and lipid digestibility estimates of different sources of oil when fed to broilers. Materials and Methods Dr. Bill Dozier at Auburn University evaluated 5 different oils when fed to broilers. Sources of oil included 1) Low FFA distillers corn oil 2) High FFA distillers corn oil 3) Palm oil 4) Soybean oil and 5) Poultry oil. Estimates of fat digestibility and AME were determined for each oil source. Results Distillers corn oil with low FFA had numerically greater AME content (8,259 kcal/kg) and fat digestibility (87.6%) than other treatments (Figures 1 and 2). Palm oil had the lowest AME content (6,355 kcal/kg) and fat digestibility (75.0%). The remaining treatments were intermediate for both AME and fat digestibility. Discussion What does the implications of this research? 1. It continues to reinforce the importance of fat digestibility in energy value calculations. Overall, those oils with greater fat digestibilities had greater AME values. However, it is important to highlight that the soybean oil treatment had a very high fat digestibility while the AME value was lower compared with the other treatments. This demonstrates that other factors are important in energy determination. 2. Compared with other oils, distillers corn oil has comparable energy values. 3. Previous research has reported AME values of 7,936 kcal/kg for low FFA distillers corn oil. Values from this study were slightly greater (8,259 kcal/kg), but very comparable. This research continues to provide confidence in the energy values nutritionists use in ration formulation.