Body Composition of Chicks Fed Complete or Incomplete Amino Acid Mixtures

Abstract

Young chicks were employed in an 8 to 21 day posthatching growth assay to determine body composition changes and protein and energy retention as influenced by dietary addition of either balanced or imbalanced mixtures of crystalline amino acids. Supplementation of either a low-nitrogen or high-nitrogen diet with an imbalancing amino acid mixture lacking isoleucine resulted in a severe growth depression. In contrast, a similar imbalancing mixture lacking lysine failed to depress chick performance. Regardless of whether the supplemental amino acid mixture was complete or incomplete, body fat concentration decreased and body protein concentration increased upon adding these mixtures to the diet.