Otherwise, horses can have free-choice water. When horses sweat considerably, salt is lost from their bodies, especially when they perform in hot, humid weather. It is recommended that free-choice, trace mineralized salt be available, especially when grain is not fed. Trace mineralized salt is preferred over plain salt. Commercial grain mixes usually have added trace minerals.
Loose salt is better for horses than block salt.
Horses are nibblers not lickers. Block salt is designed for cattle which are lickers. Some horses will learn to lick salt blocks, but others do not. Loose salt should be placed in a convenient place for horses on pasture and out of the weather if possible. Owners need to periodically check the water and salt supply in summer.