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Influence of dietary calcium on phosphorus absorption and excretion and on phosphorus-33 distribution in laying hens

Journal Article · · Poult. Sci.; (United States)
DOI:https://doi.org/10.3382/ps.0670440· OSTI ID:6768804

An experiment was conducted using isotope-dilution and comparative balance techniques to estimate urinary and fecal P excretion of laying hens fed different levels of dietary Ca. Two levels of dietary Ca (3.46 and 4.2%) were fed to eight hens for 30 days. After 30 days, 50 microCi of the radioisotope /sup 33/P was injected intramuscularly to label endogenous P. On the 2nd day after /sup 33/P dosing and at 1 h postoviposition, plasma, liver, kidney, femur bone, whole egg, ileum, ileal digesta, and excreta samples were collected from each hen. Results showed a favorable effect of increasing dietary Ca consumption (2.91 vs 3.57 g/hen per day): femur ash increased (P less than .08), excreta P decreased (P less than .03), and urinary P decreased (P less than .06). The P content of ileal digesta was not affected by dietary Ca intake, but excreta P was greater for hens consuming less Ca, indicating that, during the collection period, excretion of P in urine was increased by the low Ca diet. Endogenous P secretions constituted less than 1% of the P in ileal digesta and excreta samples and this proportion was not changed by dietary Ca consumed.

Research Organization:
Iowa State Univ., Ames (USA)
OSTI ID:
6768804
Journal Information:
Poult. Sci.; (United States), Journal Name: Poult. Sci.; (United States) Vol. 67:3; ISSN POSCA
Country of Publication:
United States
Language:
English