Four experiments were accomplished, where two for determine requirements calcium (whit- egg pullets and brown- egg pullets) and two for determine available phosphorus (white-egg pullets and brown-egg pullets). Two different phases (growing and production) were used for each experiment, where the chickens were allotted to a completely randomized design with five calcium levels (.55, .65, .75, .85, and .95%) or five available phosphorus levels (.20, .25, .30, .35, and .40%), four replicates and 12 pullets/EU for the growth phase (13 to 20 weeks of age) and eight chickens/EU for the production phase (20 to 28 weeks of age). Weight gain, feed intake, feed: gain ratio, bone resistance, ash and bone calcium (calcium experiments) or bone phosphorus (phosphorus experiments) were evaluated in the growing phase. Feed intake, egg production, egg weight, egg mass and feed conversion (g ration/g egg and kg of ration/ dozen of egg) were evaluated in the egg production phase. Calcium requirements of .832% or 634 mg/pullets/day for white-egg pullets and .782% or 605 mg/pullets/day for brown-egg pullets were estimated, and for available phosphorus requirements of .270% or 219 mg/pullets/day for white-egg pullets and .311% or 255 mg/pullets/day for brown-egg pullets.
white-egg replacement pullets; brown-egg replacement pullets; calcium available phosphorus; nutritional requirements
