title: Assessment of a bacterial 6-phytase in the diets of broiler chickens.
abstract: Two 21-d broiler experiments were conducted to assess the efficacy of a bacterial 6-phytase expressed in Aspergillus oryzae on growth performance, nutrient utilization, and intestinal molecular markers. Two hundred forty birds in 5 treatments (experiment 1) or 256 birds in 4 treatments (experiment 2) were used. The treatments included a negative control diet that was marginally deficient in P (NC) or NC plus tricalcium phosphate, 500, 1,000, or 2,000 phytase units/kg (experiment 1), and NC or NC plus monocalcium phosphate, 500 or 1,000 phytase units/kg (experiment 2). In both experiments, excreta were collected on d 19 to 21, whereas birds and feed were weighed and ileal digesta collected on d 21. For experiment 1, mucosa scraping was collected from the duodenum, jejunum, and ileum from all birds for quantification of expression level of gut level inflammatory cytokines, Toll-like receptors, and phosphate transporter (NaPi-IIb). In both experiments, tricalcium phosphate, monocalcium phosphate, and phytase supplementation improved (P < 0.05) weight gain and percentage tibia ash. Phosphorus and Ca retention and phytic acid disappearance improved (P < 0.05) with phytase supplementation (experiment 1) and there was an increase (P < 0.01) in Ca and P retention in response to phytase supplementation (experiment 2). Diets did not affect the expression of gut level cytokines, Toll-like receptors, or the mucin gene. Phytase supplementation tended to decrease (P < 0.10) the expression of NaPi-IIb. It was concluded from these studies that the bacterial 6-phytase was effective in enhancing growth of broilers receiving low-P diets as well as in increasing efficiency of P utilization and phytic acid degradation.
authors.affiliation: Avian Science Research Centre, Scotland's Rural College, Auchincruive, Ayr, KA6 5HW, UK. oluyinka.olukosi@sruc.ac.uk
authors.forename: O A
authors.initials: OA
authors.lastname: Olukosi
authors.forename: C
authors.initials: C
authors.lastname: Kong
authors.forename: F
authors.initials: F
authors.lastname: Fru-Nji
authors.forename: K M
authors.initials: KM
authors.lastname: Ajuwon
authors.forename: O
authors.initials: O
authors.lastname: Adeola
mesh_terms: D010832:6-Phytase / Q000378:metabolism / Q000494:pharmacology*; D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001236:Aspergillus oryzae / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002645:Chickens / Q000254:growth & development*; D004032:Diet / Q000662:veterinary; D005786:Gene Expression Regulation; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D055262:Mucin-2 / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D050609:Sodium-Phosphate Cotransporter Proteins, Type I / Q000235:genetics / Q000378:metabolism
chemical_list: D055262:Mucin-2; D050609:Sodium-Phosphate Cotransporter Proteins, Type I; D010832:6-Phytase; D002118:Calcium