A REVIEW OF CURRENT AMINO-ACID ESTIMATES FOR SWINE .2.

The ideal protein concept was developed from the assumption that maxim um efficiency results when all essential amino acids and nonspecific n itrogen are supplied to pigs in amounts that are not limiting and not in excess. The ideal protein is composed of a ratio of amino acids rel ative to each other. To use an ideal ratio, the requirement for a refe rence amino acid (usually lysine) must be determined using a growth as say. The requirements for the other amino acids are then determined by using the ideal ratio in proportion to the reference amino acid (rath er than doing a growth assay for each amino acid). After lysine, trypt ophan, threonine, methionine, and isoleucine are the most common limit ing amino acids in grower-finisher diets. This article summarizes the available information for determining requirements for these essential amino acids and focuses on the ideal protein concept in amino acid nu trition for grower-finisher pigs and the use of diets that are low in crude protein and supplemented with amino acids as an alternative diet formulation technique.