The investigation was carried out on 13 pregnant Holstein-Friesian heifers imported from Germany in the second trimester of pregnancy and on 10 local cows of the same breed. Blood diagnostic indices: total leukocyte counts, erythrocyte counts, haematocrit, haemoglobin, total protein, albumin, cholesterol content, aspartate aminotransferase and alkaline phosphatase activity, albumimglobulin ratio, and lysozyme activity, were measured in the cows in the perinatal period, and in the calves at the end of the first month of life. The results of the determinations indicate that immunosuppression can be a response to the stress of many hours' transport and adaptation to new maintenance conditions. The low level of total protein in the plasma of the cows' progeny (5.13 vs 6.90 g/dl in control calves) is proof of a low concentration of immunoglobulins adsorbed from colostrum. This low level is insufficient for full protection of the calves' health and is interpreted as a consequence of the long-lasting stress in cows.