Study of postnatal variability of natural resistance factors in heifers depending on ecological and technological conditions of keeping

The work has experimentally proved the effectiveness of combined prescribing of natural bioactive substances to heifers at the beginning of the newborn phases, dairy, plant-concentrate forms of feeding and insemination, taking into account iodine and selenium deficiency in the region. In this regard, research and production and laboratory studies were conducted on 3 groups of heifers-analogues of 12 heads each. They were kept from 2 to 150 days by adaptive technology, and then up to 600 days of life (the duration of experiments) - by bioindustrial. Group 1 animals were control animals; peers of groups 2 and 3 were used respectively trepel with «Polistim» and iodomidol with selenopyran in accordance with the developed schemes. They studied the age dynamics of the clinical and physiological state, cellular and humoral parameters of natural resistance. The obtained data showed that the combined administration of the studied biologically active substances to heifers was accompanied by almost the same immunostimulating effect on the body. At the same time, the thyrotropic effect in animals was much more pronounced under the conditions of using iodomidol and selenopyran than trepel and «Polistim».