Dietary energy is an expensive component of poultry diet formulations and may be as high as 60% of diets costs. Different energy evaluation systems such as apparent metabolizable energy (default system) are unable to evaluate the feedstuffs energy content accurately for poultry. Calorimetry techniques have enabled researchers to measure the wasted heat energy resulted in measuring the net energy (NE)to determine the true available amount of feeds energy and for different body functions. Net energy based feeding systems implementation in the current study confirmed the improvements in performance and egg quality and decreased diets formulation costs of laying hens.