Recent Advances in Energy and Protein Evaluation of Poultry and Pig Feeds

The cost of feed is the most important cost in pig or poultry (meat, egg, etc.) production (#6070%); the energy component represents the greatest proportion (>80%) of that cost; while protein and minerals (phosphorus mainly) supplies in feed are much less expensive but crucial for performance of animals and levels of wastes and potential pollutions in the environment. Therefore, it is important to estimate precisely the nutritional value (energy, protein, phosphorus) of feeds, either for least-cost formulation purposes (i.e. ingredients) or for adapting feed supply to energy and nutrient requirements of animals (i.e. complete feeds). In addition, in the general context of increased prices of ingredients and increased demand of human food and industry usage (biofuels, etc.), new and alternative feed ingredients and also new technologies (enzymes, for instance) will be used. Such changes must be quantified precisely in terms of nutritional values in order to obtain a representative hierarchy between feeds. Accurate, easy-to-use, ethically acceptable and cheap methods for such evaluations should also be proposed. The objectives of this paper are then to present the most recent methods and concepts for estimating the energy and protein values in both pig and poultry feeds. Some gaps, uncertainties and perspectives on this topic will also be given.