Calcium is vital for the healthy growth & maintenance of bones, teeth & hooves & also plays a number of important roles in the maintenance of general good health. Many traditional straight feedstuffs, including oats, barley & bran, are deficient in calcium & can cause an imbalance in the ratio of calcium to phosphorus in the diet. This may lead to skeletal abnormalities in the young horse, or other problems in the more mature equine. Limestone Flour is a natural & effective means of calcium supplementation but, since straight feedstuffs are lacking in many other micronutrients, a broad spectrum vitamin & mineral supplement may be more appropriate. Those horses receiving the recommended quantities of a fully balanced compound feed should require no further supplementation.