An trial was conductedto determine the best electrolyte balance (EB) for broilers from 1 to 42 daysold. In the first phase of the experiment 2,112 Ross chicks male were rearedin the floor covered with shaving woods and fed two corn-soybean meal baseddiet: one with 20 and one with 23% of crude protein (CP) combined with 0; 50;100; 150; 200; 250; 300 and 350 mEq/kg of EB. In the growing phase, 1,728 broilersof the total, remained in the experimental units and were fed only a basal diet.The experiment was analyzed as a completely randomized design with a factorialarrangement of treatments (two protein sequences and eight EB levels) and sixreplicates of 18 broilers each one. The following parameters were evaluated:weigh gain (WG), feed consumption (FC), feed efficiency (FE), carcass yield,noble cuts and the dry matter of broiler litter at 42 days of age. The bestEB estimated at 42 days were 179 (20-20% CP) and 185 (23-20% CP) mEq/kg forthe WG and similar values were found for the highest FC, 193 (20-20% CP) and192 (23-20% CP) mEq/kg. The FE (23-20% CP) had the best value estimated 159mEq/kg, lower than the values found for WG and FC. For carcass yield and noblecuts the best values obtained were similar to the performance values. The valuesobtained for the highest level of dry matter in the broiler litter were 138(20-20% CP) and 148 (23-20% CP) mEq/kg. Based on the obtained data, EB shouldbe from 160 to 190 mEq/kg for the best performance of broilers from 1 to 42days old.
