Fatma I. Hadhoud
For many years, calcium and phosphorus have been recognized as critical nutrients in growing buffalo calves’ rations. They will be discussed together since they are closely associated with each other in metabolism. The ratio of calcium to phosphorus is important as well as the minimum levels. A range of 1.2: 1 to 2: 1 is ideal. These two minerals are essential for normal bone development, clotting of blood, and maintenance of acid base equilibrium. Vitamin D is essential for absorbing calcium and phosphorus from the gut as well as for depositing the minerals in the bone. Selenium is one of the essential required minerals for growing calves. The best understood function of selenium is as a component of the enzyme, glutathione peroxidase (GSH-px). This enzyme converts hydrogen peroxide to water and is an important component of the cellular antioxidant system. In addition selenium is involved with metabolism of arachadonic acid via GSHpx. This relationship probably is one reason supplementation of selenium improves the killing ability of neutrophils. Moreover, selenium was identified as a component of Type I iodothyronine-5’-deiodinase which converts T4 to T3.
