title: Efficacy of a recombinant-derived phytase in improving the bioavailability of phosphorus in corn-soybean meal diets for pigs.
abstract: Three experiments involving 162 pigs were conducted to assess the efficacy of phytase (Natuphos; BASF, Mount Olive, NJ) in low-P, corn-soybean meal-based diets. The phytase was produced by a recombinant Aspergillus niger. The phytase supplement contained 5,000 phytase units (PTU)/g. In Exp. 1 (66 pigs) and 2 (60 pigs), growing-finishing pigs were fed fortified corn-soybean meal diets formulated to be adequate (.50%), marginal (.425%), or inadequate (.35%) in P during the growing phase (23 to 60 kg BW) followed by adequate (.40%), marginal (.35%), or inadequate (.30%) P, respectively, during the finishing phase (to 104 kg BW). Dicalcium phosphate was the source of supplemental P. In addition, the low-P sequence (.35/.30% P) was supplemented with phytase at 250, 500, or 1,000 PTU/kg. Rate and efficiency of gain decreased linearly (P < .01) and bone breaking strength decreased quadratically (P < .01) as the concentration of P was decreased in the diets. Responses in growth and bone traits to increasing levels of phytase activity in the low-P diet were linear (P < .01). The highest level of phytase in the low-P diet restored growth rate and bone breaking strength to levels that approached or met those of pigs fed the adequate P diet.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Animal Sciences, University of Kentucky, Lexington 40546, USA.
authors.forename: G L
authors.initials: GL
authors.lastname: Cromwell
authors.forename: R D
authors.initials: RD
authors.lastname: Coffey
authors.forename: G R
authors.initials: GR
authors.lastname: Parker
authors.forename: H J
authors.initials: HJ
authors.lastname: Monegue
authors.forename: J H
authors.initials: JH
authors.lastname: Randolph
mesh_terms: D010832:6-Phytase / Q000494:pharmacology / Q000592:standards*; D000821:Animal Feed / Q000032:analysis / Q000592:standards; D000818:Animals; D001682:Biological Availability; D015519:Bone Density; D005260:Female; D008297:Male; D016226:Phosphorus, Dietary / Q000032:analysis / Q000493:pharmacokinetics*; D011897:Random Allocation; D011994:Recombinant Proteins / Q000494:pharmacology / Q000592:standards; D013025:Glycine max / Q000737:chemistry / Q000592:standards*; D013552:Swine / Q000378:metabolism* / Q000502:physiology; D003313:Zea mays / Q000737:chemistry / Q000592:standards*
chemical_list: D016226:Phosphorus, Dietary; D011994:Recombinant Proteins; D010832:6-Phytase