A rich source of calcium designed to supplement bone growth requirements. NAFÕs pure Limestone Flour should be fed when there is a need for additional calcium in the diet to supplement bone growth requirements. Calcium is essential to all animals for bone and tissue growth and integrity. Calcium salts make up approximately 70% of the weight of the bone, and it is this that gives bone itÕs rigidity. Calcium also has a number of other important roles to play throughout the body. It helps in muscle contractions, particularly of the heart, and it has a role in the nerve impulse transmission in the central nervous system. Perhaps calciumÕs best known role is in milk production and it is vital that lactating mares have an adequate supply. Limestone Flour is recommended as a source of calcium for those on a ÔstraightsÕ or cereal based diet, particularly if bran is included, to balance the calcium to phosphorous ratio. A lack of calcium in the horse is seen as epiphysitis and weakness. Limestone Flour contains only ground limestone and is, essentially, pure calcium. However limestone flour is not recommended for youngstock, as excess calcium can lead to developmental abnormalities such as Osteochondrosis desicans (OCD). For youngsters requiring adequate calcium in a balanced form, see Mare, Foal and Youngstock Supplement.