Values of true digestible amino acids and prediction equations of digestible amino acids of wheat grain and wheat by-products for poultry

The true digestibility coefficients of amino acids (TDCaa) were determined and digestible amino acids prediction equations obtained, using the chemical composition of 11 feedstuffs. The feedstuffs evaluated were: brown flour meal, wheat flour, wheat grain, wheat grain residue, wheat germ, cookies residue, macaroni residue and, four wheat brans. The method of "precision feeding" with cecectomized adult rooster was utilized. A randomized complete design was used, with 11 feedstuffs and 1 fast, using six replications with I rooster per experimental unit. The average of TDC of amino acids, for the wheat bran 1, wheat bran 2, wheat bran 3, wheat bran 4, brown flour meal, wheat flour, cookies residue, macaroni residue,wheat grain, wheat grain residue, wheat germ meal were 80, 1; 76,7; 71,8; 74,5; 84,1, 94,1; 77,9; 90,1; 86,0; 90,3 e 93,1%, respectively. The best prediction equations obtained for the TDCaa values were those using crude protein (CP) and/or ether extract (EE) for lysine and,CP and/or neutral detergent fiber (NDF) for methionine, methionine + cystine, threonine and the average of the essential amino acids. The equations were: Lys = -0,8805 + 0,0755*CP + 0,0268*EE (R-2 = 98%). Met = -0,0377 + 0,0183*CP - 0,0020*NDF (R-2 = 99%), M+C = 0,0982 + 0,0273*CP - 0,0021*NDF (R-2 = 92%), Threo -0,2107 + 0,0401CP - 0,0020*NDF (R-2 = 96%), Essen = -0.1530 + 0,0451*CP - 0,0024*NDF (R-2 = 98%).