Crystalline amino acids and nitrogen emission.

Abstract

AbstractAspects of the use of crystalline amino acids in the feed to influence nitrogen excretion and nitrogen emission are discussed. To make use of amino acids in addition to feed protein, both animal and dietary factors must be considered. Possible feeding and feeding strategies including the reduction in amount of nitrogen consumed, use of highly digestible feedstuffs in the diets, and enhancement of the biological value of dietary protein are presented. Reductions in dietary protein levels and supplementation with certain crystalline amino acids is a well-established method of formulating diets to achieve a more ideal amino acid pattern and to reduce nitrogen excretion. Up to 35% reduction in nitrogen excretion may be achieved by supplementing pig diets with lysine, methionine, threonine, and tryptophan. In broilers, 41% less nitrogen was excreted upon feeding diets with 153 g CP/kg supplemented with amino acids.