Recent advances in the determination of amino acids (AA) requirements of pigs and increasing availability of feed-grade AA allow a reduction in the crude protein (CP) content of feed, while maintaining the supply of essential AA. Such diets markedly reduce nitrogen excretion without detrimental effects on nitrogen retention or growth performance. In piglets they significantly contribute to alleviate health (gut) disorders. In addition, moving from a formulation based on (minimum) CP to a formulation based on each essential AA leads to supply a better balanced AA profile (no lack and no excess), gives much more flexibility in the choice of feedstuffs, and results in a significant reduction of the feed costs.
Indeed, the impact of the high prices and volatility of the protein feedstuffs on the costs of the formulas can be reduced by implementing a more precise AA formulation strategy. For the successful implementation of this approach, an accurate knowledge of feedstuffs AA contents and the use of a net energy based system are a prerequisite. Then estimates of the response and the minimum requirements of each of the essential AA for pigs are needed to make choice of an adequate ideal AA profile and thus reduce dietary CP safely.