The objective of this work was to determine inclusion levels of sodium chloride (NaCl) in diets for male and female Colonial strain birds in the starter (from one to 28 days of age), growing (from 28 to 56 days of age) and finisher (from 56 to 84 days of age) phases reared in free-range system. In each trial, 480 birds at age corresponding to the rearing phase were housed in 24 experimental units containing areas of shelter and pasture. The experimental design used was a completely randomized in a 4 × 2 factorial arrangement (NaCl levels × sex), totaling eight treatments and three replications of 20 birds. Levels of NaCl evaluated were: 0.20, 0.40, 0.60 and 0.80% in the starter phase; 0.10, 0.30, 0.50 and 0.70% in the growing phase and 0.10, 0.25, 0.40 and 0.55% in the finisher phase. It was evaluated weight gain, feed intake, water intake, feed conversion, pH, partial pressure of carbon dioxide in the blood, hematocrit concentration and sodium and chlorine blood levels. For the starter phase it is recommended 0.53% of NaCl level in diet for birds of both sexes. For the growing phase, the levels were 0.40 and 0.43% of NaCl, respectively, for males and females, and for the finisher phase, the level of 0.25% for birds of both sexes meets the nutritional requirements.
acid-base balance; electrolyte; minerals; performance
