Effect of phytase supplementation on tissue inositol phosphate levels in broiler chickens

Sprigg, Colleen (2022) Effect of phytase supplementation on tissue inositol phosphate levels in broiler chickens. Doctoral thesis, University of East Anglia.

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Phytate, myo-inositol hexakisphosphate, serves as an essential phosphorus store in plant seeds, but has antinutritive properties in the animals that consume it. Phytases, enzymes that degrade phytate, are added to the diets of monogastric animals. Many studies have correlated the addition of phytase with improved animal performance, with a subset of these seeking to correlate animal performance with phytase-mediated release of inositol or phosphate.
This study aimed to develop methods to measure inositol phosphates in poultry tissues and to determine the effect of phytase supplementation on poultry tissues, as the effect of dietary phytase on tissue inositol and inositol phosphates and phytase mediated release of inositol and phosphate had not been studied. The study comprised wheat/soy-based diets containing one of three levels of phytase and one level of d30‰ inositol equivalent to the inositol released from total dietary phytate hydrolysis (0, 500 and 6000 FTU/kg of modified E. coli 6-phytase and 2 g/kg inositol). Diets were provided for 21 days and on day 21, digesta were collected from the gizzard and ileum, and tissues were harvested from brain, liver, kidney, breast and leg muscle, and intestinal segments. Myo-inositol and inositol phosphates were measured in diet, digesta and tissues.
Gizzard and ileal content inositol increased and total inositol phosphates reduced progressively by phytase supplementation. The predominant higher inositol phosphates detected in tissues, D- and/or L-Ins(3,4,5,6)P4 and Ins(1,3,4,5,6)P5 different from those generated by phytate degradation by E. coli 6-phytase or endogenous feed phytase, suggesting tissue inositol phosphates are not the result of direct absorption. Kidney inositol phosphates were reduced progressively with increasing phytase supplementation. These data suggest that tissue inositol phosphate concentrations can be influenced by dietary phytase inclusion rates, and that such effects are tissue specific, though the consequences of this for animal physiology and performance are yet to be elucidated.

Item Type: Thesis (Doctoral)
Faculty \ School: Faculty of Science > School of Biological Sciences
Depositing User: Kitty Laine
Date Deposited: 27 Jun 2023 12:56
Last Modified: 27 Jun 2023 12:56
URI: https://ueaeprints.uea.ac.uk/id/eprint/92516


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