Evaluation of Energy Values of Various Oil Sources when Fed to Broiler Chicks

The nitrogen-corrected apparent metabolizable energy (AMEn) values of seven different oil and fat sources used in broiler diets, primarily across the Midwestern US, were determined in a digestibility experiment. Fifteen days old, Ross 308 male broiler chicks were fed diets containing each oil or fat source at 0%, 3%, 6%, and 9% inclusion levels for 7 days before excreta samples were collected to analyze AMEn on day 21. The AMEn was calculated using 2 different methods, including a linear equation slope method as well as calculating the difference between basal diet and oil containing diets. The AMEn values determined by linear equation slope method for the oil and fat sources were generally in line with historic data. Differences in animalvegetable blended fats were observed and care should be given when using these sources in feed formulations. Direct comparison of the excess energy contributed by the 3% diets provided an average of 69% increase over the energy value derived from the equations. This increase in estimated energy can be attributed to an extra caloric effect of the additional fat due to increased digesta transit time and absorption rate of dietary energy