title: Effect of dietary phytate and phytase on proteolytic digestion and growth regulation of broilers.
abstract: This study was designed to investigate the effect of dietary phytate and phytase on proteolytic digestion and growth signalling in the gastrointestinal tract of broilers. Diets containing phytate phosphorus (2.2 or 4.4 g/kg) with phytase dose rates of 0, 500, or 1,000 FTU/kg were fed to 504 female Cobb chicks for three weeks. Diets containing high phytate reduced the activity of pepsin and trypsin, whereas the inclusion of microbial phytase increased the activity of pepsin, H(+)K(+)-ATPase, trypsin and alanyl aminopeptidase. In the intestine, phytate upregulated the mRNA expression of somatostatin, and down-regulated the mRNA expressions of ghrelin and target of rapamycin (TOR). Phytase down regulated the somatostatin gene, and upregulated the genes of ghrelin, TOR, p70 S6 kinase (S6K) and methionyl aminopeptidase. Significant interactions between phytate and phytase on the mRNA expressions of ghrelin, somatostatin and S6K in the jejunum were detected. The results suggest that dietary phytate and phytase can influence the gastrointestinal endocrine and exocrine systems, as well as the peripherally regulatory network of growth in broilers.
authors.affiliation: a Faculty of Animal Science and Technology, Gansu Agricultural University , Lanzhou , China.|b School of Livestock Science and Technology, Henan University of Science and Technology , Luoyang , China.
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
authors.affiliation: c Danisco Animal Nutrition , Singapore.
authors.forename: Ying Jun
authors.initials: YJ
authors.lastname: Ru
authors.affiliation: a Faculty of Animal Science and Technology, Gansu Agricultural University , Lanzhou , China.
authors.forename: Fa Di
authors.initials: FD
authors.lastname: Li
authors.affiliation: b School of Livestock Science and Technology, Henan University of Science and Technology , Luoyang , China.
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Wang
authors.affiliation: b School of Livestock Science and Technology, Henan University of Science and Technology , Luoyang , China.
authors.forename: Xue-Qin
authors.initials: XQ
authors.lastname: Lei
mesh_terms: D010832:6-Phytase / Q000008:administration & dosage / Q000494:pharmacology*; D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena / Q000187:drug effects; D000818:Animals; D002645:Chickens / Q000378:metabolism*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements / Q000032:analysis; D004063:Digestion / Q000187:drug effects*; D005260:Female; D041981:Gastrointestinal Tract / Q000187:drug effects / Q000502:physiology; D016226:Phosphorus, Dietary / Q000008:administration & dosage / Q000494:pharmacology*; D010833:Phytic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D059748:Proteolysis / Q000187:drug effects; D011897:Random Allocation
chemical_list: D016226:Phosphorus, Dietary; D010833:Phytic Acid; D010832:6-Phytase
keywords: broiler; growth signalling; phytase; phytic acid; proteinases