CARDIAC REACTIONS IN THE BEHAVIOUR OF YOUNG MOOSE

Using a method of telemetrical electrocardiography 40 young domesticated moose were studied in conditions approximating the natural environment at the experimental moose farm in the Pechora-Ilych Nature Reserve. An environmental physiological estimation of the ontogeny of the behavioural and emotional reactions of moose calves was done. The cardiac rhythm stabilization at value characteristic for adult animals occurred at the age of approximately 3 months. Young moose motions such as walking or pasture increased heart rate by 30-50%. Emotional positive and negative reactions are attended by cardiac chronotropic effect. The most pronounced heart rate increment (up to 250 beats per minute) was found at nursing

Morphometric Parameters, Contractility and Architecture of the Left Ventricle Myocardium in Pigs

This study aims to reveal the interrelations found within the architecture of the muscular fibers, the morphometric parameters and contractility of the left ventricular myocardium in the Landrace breed of conventional pigs. The left ventricular morphometric parameters were investigated at three levels (basal, middle, apical) utilizing echocardiography, myocardial contractility was estimated by the ejection fraction, fractional shortening and fractional thickening. The fiber architecture of the working myocardium was studied following the method of the layer-by-layer splitting of muscular fibers. The fibers ofthe superficial and deep layers of the left ventricle showed an oblique orientation, while the muscular fibers of the middle layer were distinguishable as high-lying and low-lying fibers. During the cardiac cycle, the greatest reduction in the transverse dimension and the greatest thickening of the walls were observed in the middle level when compared with the basal and apical levels, that is related with more thick layer of muscular circumferential fibers in the middle section of the ventricle and large papillary muscles. A low contractile ability of the left ventricle myocardium was revealed in pigs