Question

Regarding salt, my aged leisure horses do not touch salt blocks or licks regardless of what flavor they are (e.g., carrot, apple, mint, etc.) or whether they come from local salt mines or from the Himalayas. Exercise is light and climate mild. They are fed a full-spec vitamin and mineral supplement and a small amount of hard feed (concentrate), to which I could add salt, but is it really necessary?

Answer

As a general rule, all horses should be offered free-choice salt. Horses have an innate ability to self-regulate their sodium chloride equilibrium by consuming free-choice salt as they need it.

Horses avoid salt blocks for several reasons. Some horses have a textural aversion. If this is the case, you might offer them loose salt in a bucket (in a stall or shed) or a covered feeder (in a pasture). Other horses refuse to lick blocks that have added minerals (usually colored blocks), and switching to plain white blocks helps encourage consumption. Finally, blocks that are haphazardly tossed into a field or paddock can pick up undesirable flavors (such as manure and urine), which make them wholly unappealing to horses. Placing a new block in a container that sits above the ground and does not collect rainwater might boost intake.

You mentioned you’re feeding a “full-spec vitamin and mineral supplement,” which may contain adequate amounts of sodium and chloride to meet your horses’ needs. You can easily check the label and determine whether the amount you’re feeding will meet minimum nutrient requirements. Natural feedstuffs like your pasture do not contain significant amounts of sodium, so it is important to supplement. Average-sized horses (1,100 lb, 500 kg) at rest require 25 g of sodium chloride per day, according to Nutrient Requirements of Horses and Kentucky Equine Research (KER). The requirement increases with exercise, temperature, or humidity.