Energy Values of Brewer’s Grains and Olive Pomace Waste for Broiler Chickens Determined Using the Regression Method

Abstract

Alternative ingredients can be adequately used in poultry feeds as long as the energy values and nutrient digestibility have been previously determined. For example, brewer’s grains and olive pomace waste, which are residues of the food industry, are potential ingredients of animal feed. This study was conducted to determine the metabolizable energy (ME), nitrogen-corrected ME (MEn), and ileal digestible energy (IDE) of brewer’s grains and olive pomace waste for broiler chickens using the regression method. From day 14 to 21, 280 Cobb 500 male broilers were fed 5 experimental diets with 8 replicates of 7 birds each. The broilers were fed a corn-soy reference diet (RD) and 4 test diets (TD), where TD consisted of brewer’s grains or olive pomace waste that partly replaced the energy sources in the RD at 10 or 20% and 7.5 or 15%, respectively. The total tract metabolizability and the apparent ileal digestibility of dry matter, N, and energy as well as ME, MEn, and IDE were determined. The ME, MEn, and IDE values (kcal/kg) were 2935, 2785, and 2524 for brewer’s grains, respectively, whereas 1778, 1581, and 1394 (kcal/kg) were obtained for the olive pomace waste, respectively. This knowledge can provide useful information that helps to improve the inclusion of alternative ingredients in broilers diets and to formulate accurate feeds to meet broiler requirements.