REDUCTION OF N-EXCRETION BY SUPPLEMENTING POULTRY DIETS WITH CRYSTALLINE AMINO-ACIDS

First of all the avoidance of surplus of protein-provision is the most effective mean for reduction of Nitrogen-excretion followed by loweri ng the protein-content of the feed and maintaining the quality of the feed protein by supplementing crystalline amino acids. On the basis of results from an experiment with laying-hens it is shown that the cont ent of crude protein in use can be lowered by two percent absolute wit hout loss in performance and by three percent with only small decrease of performance. The excretion of Nitrogen is reduced by 20 and 30% re spectively. By these means an adjustment to legal requirements is poss ible within certain limits without decreasing the number of layers. Th e results of an experiment with broilers show that N-excretion can be decreased by 25% if the content of feed protein is lowered and crystal line amino acids are supplemented. Broiler feed with a very low protei n content will, however, cause unacceptable high fat content in broile r carcass.