title: Distribution of supplemental Escherichia coli AppA2 phytase activity in digesta of various gastrointestinal segments of young pigs.
abstract: The objective of this study was to determine the functional location and disappearance of activity of a supplemental Escherichia coli AppA2 phytase and its impact on digesta P and Ca concentrations in the gastrointestinal tract of pigs. In Exp. 1, 18 pigs (8.3 +/- 0.2 kg of BW) were allotted to 3 groups (n = 6 each) and fed a low-P (0.4%) corn-soybean meal, basal diet (BD), BD + phytase [500 units (U)/kg of feed], or BD + inorganic P (iP, 0.1%) for 4 wk. In Exp. 2, 30 pigs (14.5 +/- 0.2 kg of BW) were allotted to 3 groups (n = 10 each) and fed BD, BD + 500 U of phytase/kg of feed, or BD + 2,000 U of phytase/kg of feed for 2 wk. Five or six pigs from each treatment group were killed at the end of both experiments to assay for digesta phytase activity and soluble P concentration in 6 segments of the digestive tract and digesta total P and Ca concentrations in stomach and colon. Compared with pigs fed BD, pigs fed BD + 500 U of phytase/kg of feed in Exp. 1 and BD + 2,000 U of phytase/kg of feed in Exp. 2 had greater (P < 0.05) phytase activities in the digesta of the stomach and upper jejunum (2 m aborally from the duodenum). No phytase activity was detected in the digesta of the lower jejunum (2.12 m cranial to the ileocecal junction) or ileum from any of the treatment groups in either trial. Concentrations of digesta-soluble P peaked in the upper jejunum of pigs fed BD in Exp. 1 and 2, but showed gradual decreases between the stomach and the upper jejunum of pigs fed BD + phytase or BD + iP. In both experiments, pigs fed only BD had greater (P < 0.05) colonic digesta phytase activity and soluble P concentrations than those fed phytase. In Exp. 2, total colonic digesta P or Ca concentrations, or both, of pigs displayed a phytase-dose-dependent reduction (P < 0.05). In conclusion, supplemental dietary AppA2 mainly functioned in the stomach and was associated with a reduced phytase activity in colonic digesta of weanling pigs.
authors.affiliation: Department of Animal Science, Cornell University, Ithaca, NY 14853, USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Pagano
authors.forename: K R
authors.initials: KR
authors.lastname: Roneker
authors.forename: X G
authors.initials: XG
authors.lastname: Lei
mesh_terms: D010832:6-Phytase / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D000135:Acid Phosphatase / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002118:Calcium / Q000737:chemistry / Q000378:metabolism; D003106:Colon / Q000187:drug effects / Q000201:enzymology; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D004386:Duodenum / Q000187:drug effects / Q000201:enzymology; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D005766:Gastrointestinal Contents / Q000737:chemistry*; D007082:Ileum / Q000201:enzymology; D007583:Jejunum / Q000201:enzymology; D009097:Multienzyme Complexes / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D010758:Phosphorus / Q000737:chemistry / Q000378:metabolism; D013270:Stomach / Q000201:enzymology; D013552:Swine / Q000033:anatomy & histology / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D009097:Multienzyme Complexes; D010758:Phosphorus; D000135:Acid Phosphatase; D010832:6-Phytase; C118716:AppA2 protein, E coli; D002118:Calcium