Rodrigues, 2001. Rev. Bras. Zootec., 30 (6 Supplement): 2046-2058

The digestibility coefficients and thetrue digestible amino acids contents of corn and corn byproducts were determined by using cecectomized adult cockerels. Each one of the 11 feedstuffs evaluated was fed to six cockerels, consuming 15 g at 8a.m. and 15 g at 4p.m. after fastening by 24 hours. Simultaneously, six cockerels were fasted to determine metabolic and endogenous losses. After determination of the digestibility coefficients and calculation of the digestible amino acids, prediction equations were simulated to predict the corn and corn byproducts composition in lysine (LYS), methionine (MET), methionine + cystine (Met + Cys), threonine (THR) and arginine (ARG), total and digestible, based on chemical composition (crude protein - CP, crude fiber - CF, ether extract - EE and ash). The amino acids digestibility coefficients means (essential and non-essential AA) of the corn samples (1 and 2), quality protein maize and pre-cooked corn, corn gluten meal, corn gluten feed, corn germ, fine corn germ and free-fat corn germ and of the millets (1 and 2) were 92.02 e 90.69; 88.62 e 87.33; 88.40 e 85.75; 90.20 e 88.99; 95.04 e 94.84; 82.11 e 79.10; 91.84 e 91.30; 92.56 e 91.59; 87.92 e 86.18; 91.04 e 88.70; 93.55 e 93.79%, respectively. The millet shown higher amino acids digestibility and was similar to corn. The equations LYS = 0.26488 + 0.01198CP; MET = -0.01315 + 0.02031PB; Met + Cys = 0.07769 + 0.03448PB; THR = 0.05576 + 0.03410PB and ARG = 0.30805 + 0.02370PB and LYS = 0.23518 + 0.01067PB; MET = -0.02198 + 0.0195PB; Met + Cys = 0.04767 + 0.03143CP; THR = -0.01738 + 0.03156PB e ARG = 0.28013 + 0.02318PB should be used to predict the total and digestible amino acids contents, respectively, of the corn and corn byproducts.