Groups of Mineral Elements

Three groups of essential mineral elements can be distinguished (Table 3.1). For convention and historical reasons, the elements are divided into macro, trace, and ultratrace elements. The animals requirement for macro elements is 100 mg kg of food DM (dry matter), while that for trace and ultratrace 

Furthermore, an intrauterine depletion over three or more generations of an animal species has been shown to be highly effective in discovering the essentiality of several elements, especially in case of vanadium, cadmium, lead, lithium, rubidium, aluminum, arsemc, fluorine, and bromine (Anke et al. 1991b, 1998, 2001, 2001a). 

Beside the use of synthetic rations and intrauterine depletion over generations, the animal species selected for the study is also very important. The use of mminant species (goats) has allowed researchers to substitute chemically pure urea for a significant proportion of trace element-containing proteins (Mertz 1986). 

An essential element is one that is required to support adequate growth, reproduction and health throughout the life cycle if all other nutrients are optimal. Besides the deficiency group, every mineral deficiency 

The synthetic ration, when tested for the essentiality of one element, must be supplemented with all elements contained in the normal feed of the animals. The synthetic ration of the ruminants (goats), in addition to cellulose in the form of purified paper (which was used as litter and nutrient), contained all essential nutrients and all mineral elements present in the normal feed, with the exception of Ra, Fr, Ac, Po, At, Re and the rare earth metals Pr, Nd, Pm, Em, Eu, 

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