Q: Does my horse really need a salt lick?
A: The short answer is yes. Both the sodium and chloride found in a typical ‘salt lick’ (or more commonly, a mineral block) are vital to regulate body fluids, help cells function properly, create electrical impulses to fire nerves and make muscles contract, and aid in digestion. Horses lose salt through sweating; fatigue and other problems can arise if it is not replaced. Signs of salt deficiency include a rough hair coat and loss of appetite – even lowered milk production in broodmares. A 500-kg (1,100-lb) horse getting light work would need about eight to 10 grams of sodium per day; intense work would require 24-30 grams per day. Pasture and hay contain very little sodium (less than 0.1%), so manufacturers of concentrates often add sodium chloride (0.5 to 1.0%) to their products to help make up some of the shortfall. Adding a salt/mineral lick will help ensure your horse’s needs are met.
It is important to note, however, that for foals, broodmares and horses getting intense exercise, mineral blocks cannot be relied on alone to supply the proper amount of minerals their bodies require (foals, for example, require large amounts of copper). Work with your veterinarian or an equine nutritionist to be certain your horse’s diet is properly balanced for its specific needs.
What exactly is in a 50-lb salt/mineral block? Most are composed of 93-98% salt, with the balance being a variety of other minerals. Typically, it will contain macrominerals such as sodium, chloride, potassium, calcium, phosphorus, magnesium, and sulfur, plus some microminerals (trace minerals), including copper, iron, zinc, manganese, selenium, iodine, and cobalt.
Salt is the only mineral for which horses actually appear to have an appetite, and when available, most horses consume the amount their body requires without overindulging. Keep in mind the pecking order in your pasture if you have a number of horses, as the timid ones may be chased away from the block by the more aggressivetypes. A simple solution is to always have two mineral blocks a good distance apart.