Perspectives on methods for expressing energy values of poultry feed and energy requirements. 2. A proposal for net energy based on ATP potential

Most of the poultry feed in the world is formulated on the basis of ‘nitrogen-corrected apparent metabolizable energy (AMEn)’. The nitrogen correction implies that all birds are in a state of nitrogen balance (intake – excretion = 0), which is known to be false. Further, AMEn values are not additive and age dependent. A different system is therefore needed to increase formulation precision. A replacement net energy system may best be described in terms of the adenosine triphosphate (ATP)-generating potential of their nutrients, based on digestion and absorption by different classes and ages of birds and animals held under specific environmental conditions. It is time for a paradigm shift from determining feed energy values from bioassays based on antiquated 19th century concepts to estimating ATP generating capacities of ingredients on the basis of their chemical compositions and processing conditions, and utilization by different genetic stocks under each set of environmental conditions. The net energy system of Jansman et al. could be the starting point for developing a new paradigm based on the potential energetic contribution of various feed ingredients on the basis of their unique chemical compositions. This paper explains the need for a new paradigm of feed formulation strategies based on 21st century chemistry, logic and computing capacities.