Vitamin A and ß-carotene
Vitamin A and its roles, when used at the right amount:
- Rhodopsin formation, essential for vision
- Protector and regulator of epithelium formation (skin, mucosa,…)
- Involvement in antibody production supporting immunity
- Regulator of cell division cycles, supporting growth and reproduction process
ß-carotene and its roles:
- Optimizes ovarian activity
- Encourages good fertility
Main sources of vitamin A and ß-carotene:
- Grass and other green crops
- Good quality hay
This vitamin is unstable and determines the expiry date for most feeds and supplements.
Any oxidation, contact with humidity or high temperature will destroy it.
Depending on the age and physiological status of the horse, the needs vary from 12 000 to 80 000 IU of vitamin A per day.
ß-carotene is also named provitamin A, but also has its important own role. Unfortunately horses poorly transform ß-carotene into vitamin A.
Blood levels of vitamin A are strongly regulated by the amount stored in the liver and it is rare to observe any marked variation. For ß-carotene the levels depend directly on the feed intake.