Effect of an enzyme complex and dietary nutrients on endogenous losses of amino acids in chicks

Inconsistencies in expected performance have been noted from feeding exogenous enzymes. Several explanations may exist but it is possible that when feeding diets with exogenous enzymes a metabolic feedback system limits or regulates endogenous digestive enzyme expression, synthesis, and secretion. Labeled amino acids may be an advantage over other methods for measuring endogenous losses because the isotope technique may be used with practical diets. Endogenous amino acid secretions have been shown to be affected by dietary protein, types of fats, and fiber (Siriwan et al., 1989; Danicke et al., 2000) and digestible amino acid requirements should be corrected for the endogenous amino acid losses. The objectives of the present study were to determine endogenous amino acid losses from broilers fed various levels of protein, fat, and fiber with and without added Rovabio MaxTM.