Modeling the Inflow of 137Cs and 90Sr Radionuclides with Diet Into the Body of Ruminant Animals and Assessment of the Transition Into Livestock Products

The article is devoted to the issues of standardization of intake of 137Cs and 90Sr radionuclides with diet in cattle and sheep. The established and currently valid temporary averaged standards for maximum permissible content of radionuclides in feed have a number of significant shortcomings and need to be clarified. To describe and study the intake of radionuclides with diet in cattle and sheep, a simulation model is proposed, the creation of which is based on the methodology for assessing the transfer of heavy metals from feed to livestock products. A conceptual diagram reflecting the structure and functioning of the model is presented. A list of input parameters is established. The model is verified by comparative analysis of experimental data and the results of numerical modeling of the dependence of the concentration of 137Cs and 90Sr in milk and muscle mass of cattle and sheep on the content of radionuclides in the diet. The degree of correspondence between empirical data and modeling results indicates the validity of the model application to assess the transfer of 137Cs and 90Sr from the diet to livestock products and their standardization upon entry into the body. The ability to determine and know the maximum permissible levels of 137Cs and ⁹⁰Sr in diets depending on the animal species, age group, physiological state, productivity, economic purpose and other parameters will allow taking the necessary protective measures in the current radiation environment. This will also contribute to improving the technologies for keeping and feeding cattle and sheep, and guarantee the production of livestock products that meet sanitary and hygienic standards.