Folacin (folic acid or vitamin B9) and its roles:
- Essential for DNA formation and cellular division
- One of the main factors for haematogenesis in equine species
- Involvement in the synthesis of amino acids such as threonine and histidine
Folacin and its main sources:
- Green-leafed vegetables including grass
- Dried yeast
- Small amounts in cereals and pulses
Folacin is easily destroyed by ultra-violet light and must be kept in a light-tight environment.
Its main physiological function is its action as co-substrate for methylation (addition of a methyl group –CH3).
Horses kept in stables show considerably lower levels of serum folates than grazing horses. Intensive exercise over six months or more significantly decreases serum folate levels which may lead to poorer performance and endurance. The needs are estimated between 15 and 150 mg of folacin per day, depending on the physiological status. Folacin supplements are not efficiently absorbed so comparatively large daily supplies may be needed by stabled and active horses.