%0 Journal Article %T Exig¨ºncias em treonina para frangos de corte de 22 a 42 dias de idade %A Duarte %A Karina Ferreira %A Junqueira %A Otto Mack %A Filardi %A Rosemeire da Silva %A Siqueira %A Jefferson Costa de %A Garcia %A Edivaldo Ant£¿nio %A Laurentiz %A Antonio Carlos de %J Revista Brasileira de Zootecnia %D 2012 %I Sociedade Brasileira de Zootecnia %R 10.1590/S1516-35982012000100011 %X the objective of this experiment was to establish different criteria for evaluation of the requirements of digestible threonine for broilers from 22 to 42 d of age, using different regression models (quadratic, exponential, and linear response plateau). a total of 1,920 22-day-old male cobb broilers were distributed in randomized experimental design, with six treatments (six threonine levels: 0.5904, 0.6441, 0.6977, 0.7514, 0.8051, and 0.8588%) and 8 replications containing 40 broilers each one. the level of 0.6977% digestible threonine was used as standard. data on performance and carcass characteristics were evaluated. based on the data, the threonine level of 0.7642%, corresponding to the threonine:digestible lysine ratio of 71.19% had the best result for feed conversion, according to the linear response plateau model. %K digestible amino acids %K digestible threonine %K ideal protein %K performance %K regression analyses. %U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S1516-35982012000100011&lng=en&nrm=iso&tlng=en