EN
The aim of the study was to determine the activity and effectiveness of bone marrow hematopoiesis in healthy, adult cattle, and to compare hematopoietic activity levels in diseased cattle. The experimental material comprised 10 high-yielding, clinically healthy Holstein-Friesian cows aged 2-3 years. Bone marrow aspirate smears were analyzed. Marrow samples were collected with a marrow biopsy needle with a length of 63 mm (13G, from the medullary cavity of the third and fourth rib in the sternal region, and the material was subjected to a smear test. Marrow and peripheral blood smears were stained by a method proposed by May Grünwald-Giemsa (MGG). An increase in the number of orthochromatic erythroblasts with a simultaneous decrease in basophilic and polychromatic erythroblast counts was noted in this study. The results indicate that the nucleoli of bovine proerythroblasts are less visible, and the cytoplasm is stained light blue.