Related Experiment Videos
Bioavailability of various vitamin E compounds in sheep
N Hidiroglou1, L R McDowell, R Pastrana
1Animal Science Department, University of Florida, Gainesville 32611.
Summary
d-alpha-tocopherol showed superior bioavailability in sheep compared to other vitamin E forms. This natural form led to higher tissue concentrations and a larger area under the plasma alpha-tocopherol time curve (AUC).
Area of Science:
- Animal Nutrition
- Biochemistry
- Veterinary Medicine
Background:
- Vitamin E, specifically alpha-tocopherol, is a crucial fat-soluble antioxidant.
- Different forms of alpha-tocopherol exist, including natural (d-) and synthetic (dl-) isomers, as well as esterified and non-esterified forms.
- Understanding the bioavailability of various vitamin E forms is essential for optimizing animal health and productivity.
Purpose of the Study:
- To compare the bioavailability of four different forms of alpha-tocopherol (dl-alpha-tocopherol, dl-alpha-tocopherol acetate, d-alpha-tocopherol, and d-alpha-tocopherol acetate) in crossbred yearling wethers.
- To determine tissue concentrations and plasma alpha-tocopherol levels following supplementation with different vitamin E forms.
Main Methods:
- Seventeen crossbred yearling wethers were randomly assigned to four dietary groups, each receiving 400 IU/day of a specific alpha-tocopherol form.
- Blood samples were collected at baseline and at frequent intervals over 28 days for alpha-tocopherol analysis.
- Tissue samples were collected post-mortem at the end of the experiment.
- Alpha-tocopherol concentrations were determined, and plasma alpha-tocopherol time curves were analyzed to calculate the area under the curve (AUC).
- Gas-chromatography/mass spectrometry was used for alpha-tocopherol identification.
Main Results:
- Sheep supplemented with d-alpha-tocopherol exhibited higher concentrations of alpha-tocopherol in their tissues compared to those receiving other forms.
- The area under the plasma alpha-tocopherol time curve (AUC), a key indicator of bioavailability, was significantly larger in sheep fed d-alpha-tocopherol.
- Esterified forms (acetates) generally showed lower bioavailability than their non-esterified counterparts.
Conclusions:
- The natural form, d-alpha-tocopherol, demonstrates superior bioavailability in sheep compared to synthetic dl-alpha-tocopherol and its acetate esters.
- Dietary supplementation with d-alpha-tocopherol leads to greater tissue deposition and sustained plasma levels of vitamin E.
- These findings have implications for formulating vitamin E supplements in sheep diets to enhance antioxidant status and overall health.