Earth-eating and the mineral needs of livestock

Abstract

The feeding of "salts" to domesticated animals can be traced back to the time of Plutarch, and both Virgil and Pliny recommended salt for milk production. Although the value of salt has been known for centuries, it did not become common practice to feed it to domestic animals so long as they remained unimproved "starved, todbellied runts, neither fit for the dairy nor the yoke".