Urea and aspartic acid supplementation of low-protein broiler diets.

1. L-Aspartic acid does not seem useful as a protein surrogate in conventionally formulated low-protein diets for broiler chicks. 2. Urea as a protein substitute does not enhance the value of conventional broiler diets. 3. Urea does not improve broiler diets that have been supplemented with fish meal or crystalline amino acids to satisfy requirements for all indispensable amino acids. 4. Urea is absorbed into the bloodstream, but is not assimilated into body proteins.