All forms of living matter require inorganic elements or minerals, for their normal life processes. Minerals act as structural components of body organs and tissues, constituents of body fluids and tissues as electrolytes and catalysts in enzyme and hormone systems. Mineral elements cannot be synthesized by living organisms hence the minerals needs to be dietary supplemented. Supply of these minerals depends upon their contents in feeds, fodders, soils and grains. Uptake of these elements by the plants from the soil is governed by their contents in soil, soil pH, and concentration of organic matter, soil texture, and application of fertilizers, soil type, temperature and rainfall. These factors have led to a great variation in mineral contents in soil, feeds, fodders and grains. Deficiency or toxicity of minerals causing economic losses, with introduction of high yielding varieties, intensive cultivation and uses of high analysis fertilizers, there is a continuous depletion of all... Это и многое другое вы найдете в книге Mineral mixture preparation for livestock and poultry (Yasothai Ramalingam)