An experiment wasconducted with the objective of evaluating the levels digestible lysine forchickens in the starting phase (1 to 21 days of age), using two eletrolytesbalances. Eighty hundred male Cobb broilers were used, allotted in a randomizedcomplete design in a 2 × 5 factorial arrangement consisting of five levelsdigestible lysine levels (1.021; 1.276; 1.531; 1.786; 2.042) and two electrolytebalances (190 and 255 mEq/kg), with four replications and 20 chicks per experimentalunit. There was interaction for final weight, weight gain and feed intake, andfor the electrolyte balance of 190 mEq/kg the best final weight and weight gainwere observed with a 1.515% of digestible lysine. For the eletrolyte balanceof 255 mEq/kg, the best final weight and weight gain were observed with 1,801%digestible lysine. The feed:gain ratio increased linearly when the digestiblelysine was increased. The uric acid and total protein values did not differ,however the calcium levels presented interaction significant between electrolytebalances and level lysine. The digestible lysine requirement for the startingphase, from 1 to 21 days of age ranges with the electrolyte balance in the feed.
