This experiment was carried out to determine the threonine requirement for broilers chicks from 1 to 21 days of age and to evaluate the effect of different threonine levels on the uric acid excretion in broilers. One thousand and two hundred broiler chicks were randomly allotted to a 6x2 factorial arrangement, being six levels of total threonine (.73, .77, .81, .85, .89, and .93%) and two sexes, with five replicates of 20 birds each. Feed intake, weight gain, feed:gain ratio and plasma uric acid levels were evaluated. A biologic trial using the total collection of feces method was conducted to evaluate the effect of threonine level on the uric acid excretion. There were linear positive and negative effects of the threonine levels on males and females weight gain, respectively, and quadratic effect on feed intake and feed:gain ratio of males and female. The threonine levels did not influence the uric acid plasmatic levels in the birds, and was not observed effect of threonine levels on the uric acid excretion. The levels of .86% and .73% of total threonine and .73% and .62% of digestible threonine were sufficient to maximize performance of males and females, respectively.
uric acid; amino acid; broiler; digestible threonine