Since the early 1930s, manganese has been recognized to be essential for numerous physiological funtions, mostly growth and skeleton development. In the following decades, it has been identified as playing a vital role in reproductive performance and having an influence on the function of the central nervous system. In poultry its fundamental role with regard to prevention of perosis has been well established. In addition, research has demonstrated the action of manganese in calcium metabolism and hatchability. Manganese deficiency in ruminant may cause physical weakness and calves malformations such as stiffness or enlarged joints. In manganese deficiency situation, the probability of piglet mortality tends to increase soon after birth. Males raised on a Mn deficient diet are affected by sterility and sexual degeneration.
Bioavailability is an important factor when selecting sources of manganese. Manganese oxide is soluble in the gastrics juices. This characteristic is not a critical issue for the water soluble manganese salts like manganous sulphate but for the naturally water insoluble manganese oxides.Many studies demonstrate the influence of the ionic form of manganese oxides on its metabolic absorption in animal physiology. They substantiate the fact that best results are obtained with manganese oxides in valency II (Mn++ from MnO). This is why, it is recommended to specify the nature of the manganese oxide and to guarantee, in addition to the total Mn content, the content of MnO2 not to exceed 2%.
|total Manganese||- potentiometric determination|
|MnO2||- potentiometrec determination|
|Na / K / Mg / Ca||- spectro-photometric atomic absorption (AAS)|