Всероссийский научно-исследовательский институт физиологии, биохимии и питания животных – филиал Федерального государственного бюджетного научного учреждения «Федеральный научный центр животноводства – ВИЖ имени академика Л.К. Эрнста»
ABSTRACT. In the feeding of animals, sodium selenite is traditionally used as a source of selenium. In recent years, organic compounds containing trace elements have appeared on the market of feed additives, they are more readily available for absorption than mineral salts, but the ways of releasing specific metals from organic compounds and their participation in metabolism in the animal body have been poorly studied. Main sections of the review: selenium absorption, organic selenium sources, selenium assimilation, toxicity of selenium compounds, technological problems of selenium preparations use (ensuring uniform distribution of small doses in feed mixture). The ways of transformations of various feed sources of selenium in the organism are considered, the similarity of their final stages of metabolism is shown. Any substances containing selenium consumed with feed are alien to the body, since they can not be directly incorporated into the body's structures. Even selenocysteine, which is a part of enzymes, when consumed with feed, after absorption can not be included in the composition of proteins containing it, since it lacks a specific tRNA. Organic selenium-containing substances can be sources of selenium after transformations in the xenobiotic metabolism system. This is confirmed by the fact that diacetophenonylselenide (DAPS) and selenopyran induce synthesis of cytochrome P-450, which has a wide specificity and is involved in the metabolism of cholecalciferol and steroid hormones. The main effect of DAPS is realized not because of the release of selenium from it, but as a result of the biological activity of the unchanged DAPC molecule. Therefore, to consider coverage of the deficit of selenium as the main function of DAFS is not true, it should be referred to another class of biologically active substances, and accordingly the mechanism of its activity should be explained differently. This will make it possible to apply it reasonably and to obtain more stable results in practice. Considering that substances containing selenium are introduced into the feed in micro doses, information on the particle size should be requested from premix suppliers on the particles size and guarantee their availability in a portion of feed with a coefficient of variation of no more than 5%, provided that the preparation is used with uniform particles.
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