The nutritional calcium (Ca) levels were determined for ISA Label broilers in the starter (1 to 28 days), growing (28 to 56 days), and finishing (56 to 84 days) phases. Three trials were conducted, one for each phase and in each trial, 480 birds with age corresponding to the phase were housed in 24 experimental units with shelter and pasture areas. The experimental design was completely randomized in a factorial arrangement of 4x2 (Ca levels and sex), totaling eight treatments with three replicates of 20 birds. Body weight gain (BWG); feed intake (FI); feed per gain (FG); contents of phosphorus (TP), calcium (TCa) and ash (TA) in tibia; and bone breaking strength (BSB) were evaluated. At the starter phase, 1.16% of Ca is recommended in the diet for birds of both sexes. At the growing phase, 0.78 and 0.88% of Ca for males and females, respectively, are recommended and at the finishing phase, the level of 0.69% of Ca is recommended in diet for both sexes.
broilers; phosphorus; slow-growing birds; nutritional requirement
