Under the conditions of Kabardino-Balkarian Republic, the thyroid gland of cows is influenced by the biosphere and the habitat of animals characterized by iodine deficiency. The forms of goiter lesions, their frequency and nature indicate the unity of the phylogeny and ontogenesis of the thyroid gland in humans and cattle, as well as the unity of pathogenesis in all mammals. It has been established that the conditions of the organism's existence and any changes in the external environment first affect the function, and then the structure of the endocrine glands. In turn, the structure of the endocrine glands determines their functional activity and thus affects the processes of growth and development of animals. This position indicates that a comprehensive study of the structure and function of the endocrine glands, including the thyroid gland, as the main depot of iodine in the body, in the iodine-deficient zone will play an important role in improving the productive qualities of farm animals. Thus, under the conditions of the iodine-deficient territory of Kabardino-Balkarian Republic, the thyroid gland of the Schwyz breed cows lacks iodine in the biosphere, and this is reflected in its functional state, against which pathomorphological changes develop. This circumstance dictates the need to organize preventive measures by replenishing the diet with missing elements, in which the leading role belongs to iodine.

Pilov Aues Kh., Tarchokov Timur T., Poidenko Anastasiya A., Miller Tatyana V.

1. Tuaeva E. V., Sharvadze R. L., Babukhadiya K. R., Pankratov V. V. Optimizatsiya mikromineral'nogo pitaniya remontnykh telochek putem ispol'zovaniya asparaginatov belka soi [Optimization of trace elements of composition in replacement heifers’ diet with the help of soy protein asparaginates]. Dal'nevostochnyj agrarnyj vestnik. – Far Eastern Agrarian Bulletin, 2018;4 (48):224–227 (in Russ.).
2. Sharvadze R., Gaidukova E., Krasnoshchekova T., Babukhadiya K., Burmaga A. Influence of biologically active compounds on milk production and metabolism of lactating cows. E3S Web of Conferences, 2020. P. 01005.
3. Botasheva V. S. Rol' oblastei yadryshkovykh organizatorov v dinamike predopukholevykh protsessov i opukholei shchitovidnoi zhelezy [The role of nucleolar organizer regions in the dynamics of pretumor processes and thyroid tumors], Stavropol', SAT-Print, 2000, 16 p. (in Russ.).
4. Braun A. A. O morfologicheskom indekse funktsional'noi aktivnosti shchitovidnoi zhelezy [On the morphological index of the functional activity of the thyroid gland]. Proceedings from 2-aya Nauchnaya konferenciya – 2nd Scientific Conference. (PP. 20–23), Andizhan, 1966 (in Russ.).
5. Pilov A. Kh. Morfofunktsional'naya kharakteristika shchitovidnoi zhelezy domashnikh zhivotnykh v usloviyakh Tsentral'noi chasti Severnogo Kavkaza [Morphofunctional characteristics of the thyroid gland of domestic animals in the conditions of the Central part of the North Caucasus]. Extended abstract of doctor’s thesis. Stavropol', 2003, 50 p. (in Russ.).
6. Pilov A. Kh. Patomorfologicheskii analiz shchitovidnoi zhelezy domashnikh zhivotnykh [Pathological analysis of the thyroid gland of domestic animals]. Morfologiya. – Morphology, 2016; 3: 162–163 (in Russ.).
7. Glod D. Yu. Sravnitel'naya morfofunktsional'naya kharakteristika shchitovidnoi zhelezy u plotoyadnykh [Comparative morphofunctional characteristics of the thyroid gland in carnivores]. Extended abstract of candidate’s thesis. Moskva, 2009, 18 p. (in Russ.).
8. Cherkasova Yu. B., Zhemchuzhnikova А. А. Morfologicheskie osobennosti shchitovidnoi zhelezy v khronodinamike postradiatsionnogo perioda nablyudeniya [Morphological features of the thyroid gland in the chronodynamics of the post-radiation observation period]. Proceedings from Topical issues of morphology: Simpozium s mezhdunarodnym uchastiem – Symposium with international participation. (PP. 16), Smolensk, Smolenskaya gosudarstvennaya meditsinskaya akademiya, 2014 (in Russ.).
9. Grebenshchikov A. V. Funktsional'naya morfologiya shchitovidnoi zhelezy u telyat v usloviyakh ekologicheskogo neblagopoluchiya [Functional morphology of the thyroid gland of calves in conditions of ecological trouble]. Extended abstract of candidate’s thesis. Voronezh, 2001, 22 p. (in Russ.).
10. Zolnikova I. F. Strukturno-funktsional'naya otsenka adaptatsii shchitovidnoi zhelezy i nadpochechnikov ondatry v usloviyakh Baikal'skogo regiona i pri antropogennom vozdeistvii [Structural and functional assessment of the adaptation of the muskrat thyroid gland and adrenal glands in the conditions of the Baikal region and under anthropogenic influence]. Extended abstract of candidate’s thesis. Blagoveshchensk, 2021, 23 p. (in Russ.).
11. Danilenko V. N., Onufrieva V. V., Filin A. A. Novye gistologicheskie osobennosti v traktovke kharaktera uzlovoi patologii shchitovidnoi zhelezy [New histological features in the interpretation of the nature of nodular pathology of the thyroid gland]. Morfologiya. – Morphology,
    2019; 155; 2: 95 (in Russ.).