Project Details
Projekt
Myo-inositol and low-P supply effects on intestinal processes of InsP6 degradation, absorption, and P utilisation in two contrasting high-yielding laying hen strains
Applicant
Professor Dr. Markus Rodehutscord
Subject Area
Animal Breeding, Animal Nutrition, Animal Husbandry
Term
since 2017
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 322916021
Previous studies using young chicken and quail have shown large variation in phosphorus utilization related to intestinal phytic acid (InsP6) degradation and caused by both dietary variables and the genetic background of the birds. Laying hens are specific because they need very high dietary calcium but low phosphorus concentrations in the laying period, but their requirements drastically change during lifespan. Therefore, the objective of the proposed project is to characterize degradation products of InsP6 and mucosal activity of phytase and alkaline phosphatase in laying hens in dependence on age, genetic background, and dietary variables. Two experiments are conducted using Brown and White Leghorn hybrids that show a substantial degree of genetic differentiation (FST=0.25). Experiment 1 will be conducted at around peak of egg production when the hens are approximately 30 weeks old. Dietary variables are the concentrations of phosphorus and calcium, and together with the hybrid variable they are arranged in a 2×2×2-factorial, using ten individual hens per treatment. In Experiment 2, the hybrid and the age of hens are the experimental variables. Samples are taken when hens are 10, 16, 24, 30, and 60 weeks old, using ten individual hens per treatment. Diets are adjusted to the specific requirement in each age period, but are the same for all hens. In both experiments, the appearance of lower inositol phosphate isomers, myo-inositol, calcium and phosphorus will be studied in content of crop, gizzard, duodenum/jejunum, ileum, and ceca. Disappearance is calculated by using titanium dioxide as the indigestible marker. Mucosal enzyme activities are measured in vitro using isolated apical membranes from the upper small intestine. Concentrations of myo-inositol are also studied in blood plasma and eggs. All hens are genotyped using the Illumina 60K chicken Infinium iSelect chip in project 2 of the Research Unit. Samples needed in projects 3, 4, 5, 7, 8, and 9 of the Research Unit are taken at the same time using a jointly developed sampling protocol. In addition to answering the specific research questions of this project, all data will be integrated into the bioinformatics data handling and network building made in project 9 and exchanged with the other projects in order to test the overarching hypotheses of the proposed Research Unit.
DFG Programme
Research Units
Co-Investigator
Professorin Dr. Korinna Huber
