The objective of this experiment was to determine the digestible lysine requirement for male broilers in the period from 22 to 42 days. Four hundred and sixty male broilers Hubbard, with an initial average weight of 631 g, were allotted in a randomized block experimental design with five treatments, six replicates and 15 birds by experimental unit. The treatments corresponded to five L-lysine levels supplemented to a basal diet with 19,64% of crude protein and 3100 kcal of ME/Kg resulting in diets with .80, .86, .91, .97, and 1.02% digestible lysine. The true amino acid digestibility in the basal diet was determined by means of a digestibility trial with cecectomized Leghorn roosters. There was effect of digestible lysine levels in the diet on the weight gain (WG), diet intake, feed:gain ratio (F:G) and lysine intake, but there was no effect on the uric acid concentration in the blood serum, in the carcass chemical composition and carcass yield, including breast and hind quarter yield. Based on the WG and F:G results, the digestible lysine requirements was estimated in 1.02 and .98%, respectively.
lysine; broiler chicks; finishing phase; male