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Updated: Jul 18, 2026
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Quantitative Analysis of Dietary Vitamin A Metabolites in Murine Ocular and Non-Ocular Tissues Using High-Performance Liquid Chromatography
Published on: December 27, 2024
Bioavailability of vitamin A sources for cattle
C E Alosilla1, L R McDowell, N S Wilkinson
1Department of Animal Sciences, University of Florida-IFAS, Gainesville 32611, USA.
Journal of Animal Science
|December 21, 2006
Summary
This study compared five vitamin A sources in cattle diets. Microvit A and Rovamix A showed the highest bioavailability, indicating differences in how protected vitamin A supplements are from rumen destruction.
Area of Science:
- Animal Nutrition
- Nutritional Biochemistry
- Ruminant Physiology
Background:
- Vitamin A is essential for cattle health and productivity.
- Dietary vitamin A bioavailability can be influenced by feed processing and gut environment.
- Protective coatings on vitamin A supplements aim to enhance delivery to the animal.
Purpose of the Study:
- To evaluate the bioavailability of five different vitamin A sources in cattle.
- To determine if protective coatings affect vitamin A absorption and tissue deposition.
- To compare the efficacy of various commercial vitamin A supplements.
Main Methods:
- Fifty-three yearling cattle were fed high-concentrate diets supplemented with different vitamin A sources for 84 days.
- Liver and plasma samples were collected every 28 days to measure retinol concentrations.
- Statistical analysis was performed to compare treatment effects on retinol levels.
Main Results:
- All supplemented vitamin A groups showed significantly higher liver retinol concentrations than the control group.
- Microvit A and Rovamix A treatments resulted in numerically higher liver retinol concentrations.
- No significant differences in liver retinol were observed among most supplemented groups by the end of the study.
Conclusions:
- Vitamin A supplementation significantly increased liver retinol concentrations in cattle.
- Microvit A and Rovamix A appear to be the most bioavailable vitamin A sources evaluated.
- Rumen protection likely plays a role in the bioavailability of vitamin A supplements.
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