Assessment of extruded grain amaranth as a feed ingredient for broilers. 2. Apparent amino acid availability values

Apparent amino acid availabilities (AAAA) were determined for grain amaranth in two experiments using broilers. Total collection method (TCM) and acid-insoluble ash (AIA), as a marker, were used for these determinations. Individual amino acid availabilities for the extruded grain were calculated both by regression analysis and by difference from the basal diet. From the linear regression equations, TCM produced more accurate results than did the AIA method, based on standard errors of the intercept and coefficient of determination. Predicted AAAA, based on linear regression equations, from the TCM were 92.4, 79.9, and 89.4% for methionine, lysine, and arginine, respectively. Using the TCM and calculation by difference, average AAAA on an as-fed basis were 85.0, 79.1, and 92.9% for methionine, lysine, and arginine, respectively. The AAAA of 11 other amino acids were also determined.