amino acid analysis of blood and feed samples was performed using a method provided by BOCM PAULS Ltd. (Ipswich, UK) laboratory. samples were oxidized with a hyfrogen peroxide-formic acid-phenol mixture. excess oxidation reagent was decomposed with sodium metabisulfite. the oxidized samples were hyfrolyzed with 6M hydrochloric acid for 24h. the hydrolysate was adfusted to pH2.2, centrifuged, and filtered.amino acids were separated by ion exchange chromatography (Biochrom 20+ amino acid analyzer, biochrom Ltd.,Cambridge, UK) and determined by reaction with ninhydrin using photometric deterction at 570nm (440NM for pro