Good nutrition = good health. Essential nutrients to support horses that are on pasture only, sweat a lot, or in recovery (stalled, in lay-up, or prone to tie-up).
Vitamins, minerals, and anti-oxidants are the primary nutrients required for life. Horse feeds and supplement labels will show the minimum guaranteed analysis per feeding, but that doesn't always meet the individual needs of a horse (whatever the reason). Adding a specifically balanced formula assists with meeting nutritional requirements, especially when the horse is in hard work, or in rehabilitation for illness or injury.