Abstract
This study was realized with the objective to determine the apparent and standardized digestibilities of phosphates to pigs in growing phase, employing two methodologies. Forty-two crossbred barrows with an initial weight of 37 ± 1.1kg were used in a randomized-block design in a 2 × 7 factorial arrangement, with two collection methods: total fecal collection and the use of a indicator (acid insoluble ash [AIA]) × seven treatments, which consisted of a control diet (CTR); three diets containing phosphate in powder form (PP): PPA= CTR + powder phosphate A, PPB = CTR + powder phosphate B, and PPC= CTR + powder phosphate C; and another three diets containing the microgranular phosphate (MP): MP15 = CTR + microgranular phosphate 15%, MP45 = CTR + microgranular phosphate 45% and MP75 = CTR + microgranular phosphate 75%). The values of 15, 45, and 75% correspond to the water-solubility of the phosphates. There were six replicates, and the pig was considered as experimental unit. The standardized digestibility coefficients of the phosphates assessed by the total collection method, in percent values, were: PPA = 86.9, PPB = 84.9, PPC = 81.9, MP15 = 89.4, MP45 = 88.8, and MP75 = 92.6. The standardized-digestibility coefficients of the phosphates evaluated by the indicator method (AIA) in percent values were: PPA = 75.9, PPB = 75.4, PPC = 75.6, MP15 = 84.9, MP45 = 78.0, and MP75 = 79.4. Considering the two methodologies evaluated in the present work, the microgranular phosphates constitute the best alternative for feeding pigs in the growth phase.
fecal indicator; in vitro solubility; minerals; particle size
