Study on Zn relative concentration and state in sheep duodenum by XAFS

Area of Science:

• Animal Science
• Nutritional Biochemistry
• Spectroscopy

Background:

• Zinc is essential for animal health, but its absorption varies significantly with source.
• X-ray absorption fine structure (XAFS) spectroscopy offers a novel method to study mineral absorption dynamics.
• Understanding zinc bioavailability is crucial for optimizing animal nutrition and health.

Purpose of the Study:

• To investigate zinc absorption and concentration changes in sheep duodenal tissue using different zinc sources.
• To evaluate the efficacy of synchrotron-based XAFS spectroscopy in assessing zinc bioavailability in animal models.
• To compare the absorption of inorganic zinc (ZnO, ZnSO4) versus organic zinc (ZnMet, ZnLys) and their complexes with amino acids.

Main Methods:

• Utilized the everted intestinal sac technique with sheep duodenal explants incubated in vitro.
• Applied X-ray absorption fine structure (XAFS) spectroscopy to analyze zinc oxidation state and relative concentration.
• Employed atomic absorption spectrometry (AAS) for independent verification of zinc concentration.

Main Results:

• Organic zinc sources, particularly ZnMet, resulted in higher zinc concentrations compared to inorganic sources (ZnO, ZnSO4) (P < 0.05).
• XAFS results were consistent with AAS, confirming the accuracy of the spectroscopic method.
• Organic zinc was dissociated into ions and absorbed as inorganic zinc, indicating enhanced bioavailability.

Conclusions:

• Organic zinc is more readily absorbed than inorganic zinc in sheep, likely due to dissociation into absorbable ions.
• XAFS spectroscopy is a viable and effective tool for studying mineral absorption in animal intestinal tissues.
• Methionine or lysine ligands reduced inorganic zinc absorption, suggesting a need for further research into optimal inorganic zinc and ligand ratios.