The effects of concurrent increases in supplementation of calcium and phytase on growth performance, balance of Ca and P, and bone mineralization in nursery pigs

Abstract The objective of this study was to investigate the effects of concomitantly increasing supplementation of Ca and phytase on growth performance, balance of Ca and P, and bone mineralization in nursery pigs. There were eight experimental diets. The positive control (PC) one and two were formulated to contain 0.64% and 0.85% total Ca, respectively, whereas the dietary concentrations of other nutrients were identical and adequate. The negative control (NC) was deficient in total Ca (0.48%) and total P (0.41%). Five combinations of incremental levels of Ca and phytase (0.48% and 1,750 phytase units [FYT]/kg, 0.52% and 2,000 FYT/kg, 0.55% and 2,250 FYT/kg, 0.59% and 2,600 FYT/kg, and 0.63% and 3,000 FYT/kg) were added to the NC to establish the remaining five experimental diets. Each diet was fed to six pens of six pigs (three barrows and three gilts per pen). All diets contained 3 g/kg TiO2, and fecal samples were collected from each pen during the trial. In the end, one pig per pen was euthanized to collect the right tibia and urine in bladder. The results showed that the pigs of NC gained less weight, consumed less feed, and utilized feed less efficiently than their counterparts fed the PC and the treatments with phytase (P