As a feed consultant I hear quite often “My horse has plenty of hay and a salt block with selenium. That’s enough to meet all his nutrition needs, right?” My answer is always, resoundingly, “NO.” The truth of the matter is, while salt does have its place in the equine diet, the nutrient needs of a horse are much more complex than what a salt block with trace minerals can provide. So if you are depending on a trace mineral salt block to provide anything to your horse’s diet except for a source of salt, I would encourage you to keep reading.
Typical salt blocks are 95% or more salt and less than 5% mineral, so they do very little to meet the mineral needs of the horse. In addition, horses are usually inefficient at consuming salt in block form. They will lick for a short period of time each day on a salt block, but will not consume the sheer amount of minerals needed to have any effect on their nutrient needs.
A better solution to get your horse all the nutrients he needs is to provide a fortified feed that is fed according to tag directions. This will ensure that your horse’s needs for many things, including energy, protein, vitamins and amino acids in addition to minerals are being met. Then, provide loose white salt, which horses will more freely and easily consume, alongside the feed in a separate container. As always, be sure to provide plenty of fresh, clean water at all times, as consuming salt will also often increase water consumption.