Analysis of electrocardiogram registration methods and features of some ecg indicators in early postnatal calves

This article presents studies of various methods of fixing electrodes for recording electrocardiograms, testing of the selected method on live models in a livestock complex, as well as an assessment of electrocardiographic indicators of calves in the early postnatal period. The results of the literature review prove that the methods of fixing electrodes when recording ECG in cattle have their own characteristics. Due to these characteristics, it is impossible to extrapolate fixation methods from humane medicine or companion animal clinics. Such differences are also due to the physiological features of cardiac contraction: depolarization of the ventricles in cattle occurs simultaneously from the epicardium and endocardium, and not sequentially, as in carnivores. The methods of fixing the electrodes according to M.P. Roshchevskiy, E.F. Dymko, and also the method of T.V. Ippolitova were analyzed. In our opinion, the optimal method for cattle is the sagittal leads method proposed by M.P. Roshchevskiy. This is confirmed by the results of a series of studies conducted by the authors on productive animals in the conditions of a livestock complex. According to the obtained data, the heart rate of the calves included in the sample averaged 136.27±11.129 bpm, PR interval was 0.15±0.019 sec, QRS complex was 0.05±0.005 sec, QT interval was 0.25±0.017 sec, ST interval was 0.21±0.017 sec, TP segment was 0.07±0.041 sec. and RR interval was 0.42±0.129 sec. All obtained electrocardiograms were suitable for interpretation, with a minimum of artifacts from limb movements. It should be noted that in order to reduce the number of artifacts on the electrocardiogram caused by the motor activity of the calves, the readings were taken in a specially designed machine. The use of the technique of fixing electrodes in calves using the sagittal lead system with limited animal mobility in a special machine allows obtaining a high-quality electrocardiogram that is easy to decipher.