Calcium and phosphorus which constitute about 70 % of the minerals in the body are generally evaluated together. Calcium and phosphorus are collectively incorporated in the structure of teeth and bones; 99% of the calcium and around 80% of phosphorus are found in teeth and bones. Since the Ca amount in the newborn animals are limited, a significant amount of Ca is needed during the growth, development and calcification of the bones. Calcium also have functions in vital metabolical processes. The control of blood Ca levels by parathyroid and adrenal glands shows the physiological significance. When the mineral is needed it is taken from stored calcium inside the bones. When the blood Ca level rise, it is stored to be used when it is needed. The main reason for Calcium deficiency is the sodium value in the ration. An animal’s over-consumption of sodium causes calcium to be excreted in urine. As a result of this loss, visible bone problems emerge in the animals. The most evident results of calcium and phosphorus deficiencies can be observed in bone development. In the deficiencies of these minerals, bones continue to develop, but cannot be hard enough. As a result, rachitis characterized with visible bone disorders in the young animals, and osteomalacia in the old ones are seen. Ca and P are critical minerals which have to be included in the rations for egg and milk production. Additionally Ca is needed in order to avoid bone disorders. Hens produce eggs with thin and soft shells when they are fed less than needed Ca. Egg production and hatchability decrease when the Ca is insufficient in the rations. Cows react to this insufficiency by decreasing the milk yield. Phosphorus, which has an effect on the bone development and metabolism together with calcium, has also distinctive functions in the body. It functions in: keeping the blood Ca levels within the optimal limits, carbohydrate metabolism, participate in the structures of nucleic acids, phosphoproteins which enables the permeability of cell membrane, and in the structures of high-energy phosphates like hexosephosphate, adenosine phosphate, creatine phosphate, transport and metabolism of lipids, and participate in the structures of phospholipids which have a crucial importance for the cell membranes, energy metabolism. Phosphorus is a component of RNA and DNA which are necessary for cytogenesis and consequently for protein synthesis. Aside from these, it also participates in the structures of several enzymes. Phosphorus deficiency is a widespread problem which can be seen in any part of the world in any type of animals. The first symptom of this mineral deficiency is the loss of appetite which is common. In case of a severe deficiency in the layer hens, loss of appetite, weight loss and death can be seen in 10-15 days. It is a necessity to add phosphorus to the rations of both of the poultry and monogastric animals which cannot adequately utilize phosphorus from plant origin, and of the ruminants which are fed with the rations based on roughage. Roughage generally has a certain amount of phosphorus. Clean, cleared of any cause of diseases bone meals, defluorinated phosphate rocks, and particularly DCP (Dicalcium Phosphate) and MCP (Monocalcium Phosphate) are convenient phosphorus sources.