PSIV-13 Supplemental phytase increases phosphorus digestibility in pigs regardless of phytase source or feed pelleting

摘要

Two experiments were conducted to investigate the effects of phytase source and feed pelleting on digestibility of dry matter (DM), crude protein, organic matter (OM), and phosphorus (P) with different doses of phytase in pigs. In Exp. 1, ten barrows (31.4 ± 3.5 kg of BW) were individually housed in metabolic crates and allotted to a replicated 5 × 6 Latin square design with 5 diets and 6 periods. In Exp. 2, ten barrows (28.2 ± 3.2 kg of BW) were individually housed in metabolic crates and allotted to a replicated 5 × 5 Latin square design with 5 diets and 5 periods. Each period lasted 10 d consisted of a 5-d adaptation and a 5-d collection periods and the marker to marker method was used for fecal collection. In both experiments, a basal diet was prepared based on corn and soybean meal without phytase or inorganic P. Four additional diets were prepared in a 2 × 2 factorial treatment arrangement with 2 phytase sources (Buttiauxella spp. or Escherichia coli) and 2 feed forms (mash or pellet). Both experiments employed the same treatments but had different supplemental phytase doses (500 and 1,500 FTU/kg in Exp. 1 and 2, respectively). In Exp. 1, supplemental phytase increased standardized total tract digestibility of P (66.1 vs. 51.7%; P < 0.001) with no effects of phytase source or feed pelleting. Feed pelleting increased digestibility of DM, crude protein, and OM (P < 0.001). In Exp. 2, supplemental phytase increased standardized total tract digestibility of P (72.8 vs. 44.8%; P < 0.001) with no effects of phytase source or feed pelleting. Feed pelleting increased digestibility of DM and OM (P < 0.001). Taken together, supplemental phytase at 500 and 1,500 FTU/kg increases P digestibility regardless of phytase source or feed pelleting.