The article presents electrophysiological studies on the analysis of variation pulsograms by the method of mathematical analysis of heart rate variability of the electrocardiogram. On this basis reference values were obtained and breed characteristics of the Yakut aboriginal cattle of the Republic of Sakha (Yakutia) were established. Cardiointervalometry assesses the state of vegetative homeostasis and also considers the interaction of the sympathetic and parasympathetic divisions of the autonomic nervous system, namely the autonomic and central heart rhythm control circuit. Evaluation of the functional state of the body by heart rate variability is one of the methods of non-invasive control of humoral and autonomic nervous regulation. The object of the study in the work was the Yakut aboriginal cattle of the Republic of Sakha (Yakutia) of different age groups. Functional indicators of the cardiovascular system as integral criteria of the adaptive capabilities of the body are the leading indicators reflecting the balance between the body and the environment. The mechanisms of vegetative regulation play a major role in ensuring the adaptive reactions of the organism and maintaining homeostasis when the environment changes. For the analysis and recording of the electrocardiogram in the animals under study, a complex portable electrophysiological laboratory (program CONAN-4.5 in the frontal leads system according to the methodology of M. P. Roshchevsky) was used. Clinical research methods were carried out according to the methods of clinical examination of animals by B. V. Usha and included examination, palpation, percussion and auscultation of the cardiac region. As a result of the research work, the indicators of variation pulsometry were obtained and physiologically substantiated, such as primary and secondary indicators of Baevsky, Kaplan indices, as well as indicators of cardiac stress and cardiac arrhythmia.

Stepura Evgeniy E., Fedorov Valery I.

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