The Role of Bone Phosphorus, Calcium and Magnesium on Bone Reserves of Indigenous Mixed Breed Cattle Grazing Natural Pasture during Times of Mineral Stress Induced by Drought in Mogosane Village of North West Province, South Africa

Background: Bone consists of Ca and P deposited within an organic collagen matrix. The highly porous nature of this matrix provides bone with an extensive surface area, making bone a highly labile source of both Ca and P and serves as metabolic reservoir for Ca, P and other minerals. Phosphorus in the skeleton provides large reserve, which may be mobilized when the diet is deficient in phosphorus, the measurement of bone minerals is important to evaluate bone reserves such as bone volume, bone specific gravity and bone thickness. Methods: Ten male mix breed cattle between the ages of 6 and 12 months therefore, were randomly selected from a herd feeding exclusively on communal grazing and receiving no supplements and were used to determine the role of bone phosphorus, calcium and magnesium on bone reserves in cattle grazing natural pasture. Bone samples were analysed for P through the FASPac II Version R2MI Auto- Analyzer and were analysed for Ca and Mg through an Atomic Absorption Spectrometer. Results: Bone volume, bone specific gravity and bone thickness were reacting with same pattern almost throughout research. Grass phosphorus was positively correlated to bone Mg (r(2)= 0.466) with the P value of 0.053. Concentration of Ca in the grass was positively correlated to bone Mg (r(2)= 0.524) and bone specific gravity (r(2)= 0.593) with the P values of 0.051 and 0.048 respectively. The rainfall measured during the research shown to have positive correlation on the concentration of P in the grass r(2)= 0.690) and of Mg (r(2)= 0.848) with the P values of 0.04 and 0.001 respectively.