Duarte, Karina Ferreira [UNESP]Junqueira, Otto Mack [UNESP]da Silva Filardi, Rosemeire [UNESP]de Siqueira, Jefferson CostaPuzotti, Maíra MangiliGarcia, Edivaldo Antonio [UNESP]de Britto Molino, Andrea [UNESP]de Laurentiz, Antonio Carlos [UNESP]2014-05-272014-05-272013-10-14Revista Brasileira de Zootecnia, v. 42, n. 10, p. 728-733, 2013.1516-35981806-9290http://hdl.handle.net/11449/76845The objective of this experiment was to establish different criteria to evaluate the requirements of digestible tryptophan for broilers from 22 to 42 d of age, using different regression models (quadratic, exponential and Linear Response Plateau) and in case of statistical significancethecomparisonofmeansbyDuncantestat5%probabilitywasalsoadopted.Atotal of 1,920 Cobb 500 male broilers were distributed in a completely randomized experimental design, with 6 treatments (6 digestible tryptophan levels: 0.1395, 0.1610, 0.1825, 0.2040, 0.2255 and 0.2470%) and 8 replications containing 40 broilers each. Performance and carcass characteristics were evaluated. The level of 0.2255% of digestible tryptophan numerically improves feed conversion, and the 0.1919% estimated by the quadratic equation significantlyimprovescarcassyield. © 2013 Sociedade Brasileira de Zootecnia.728-733engDigestible amino acidsIdeal proteinPerformanceRegression analysisArtigo10.1590/S1516-35982013001000006S1516-35982013001000006WOS:000324596700006Acesso aberto2-s2.0-848851108242-s2.0-84885110824.pdf8942267939443572