INFLUENCE OF GUANIDINATION ON APPARENT ILEAL AMINO-ACID DIGESTIBILITYIN SOME PROTEIN-SOURCES FOR BROILERS

High pH employed during the guanidination process (conversion of lysin e residues to homoarginine) and its possible effects on racemization o f amino acid residues to D-forms and on amino acid digestibility are c oncerns often raised with the use of guanidinated proteins to estimate endogenous amino acid losses in monogastric animals. The objective of the present study was to investigate the influence of guanidination o n apparent ileal amino acid digestibility of casein, soybean meal, cot tonseed meal, and canola meal for broiler chickens. Apparent ileal dig estibility of amino acids in guanidinated and unreacted proteins, with few exceptions, were found to be remarkably similar. These results su ggest that the guanidination process has no influence on the susceptib ility of proteins to proteolysis and that racemization is not a practi cal problem when the proteins are guanidinated at low temperatures.