The study was performed on 21 H-F calves divided into 3 groups of 7 animals each. The first group was composed of calves whose mothers did not receive an injection of Se preparation. The second and third groups consisted of calves whose mothers were administered injections of Se and vitamin E in a single dose of 10 ml and 30 ml, 10 days before the expected parturition date. 24 hours after birth, blood samples were collected from all calves to determine Se, Fe and IgG concentrations and the activity of GSH-Px and GGT. The results of the study indicate that the administration of a single-dose Se supplement to cows in late pregnancy increases Se concentration in calves and promotes passive transfer of immunity from the mother to offspring.

Cytological evaluation of bone marrow smears stained by May-Grünwald Giemsa method was performed. The smears came from 20 fallow deer (Dama dama) 3 days old divided into 2 groups each consisting of 10 animals. The experimental group (E) received intramuscularly selenium and vitamin E at a dose of 3.0 ml (tocopherol acetate – 50 mg, sodium selenite – 0.5 mg, solvent - 1 ml) in the 3rd day of age. The control group (C) did not receive any supplementation or placebo. For hematological analyzes blood was collected three times: on 0, 15th and 25th day of the experiment. Serum concentration of selenium and vitamin E was determined using high perfor- mance liquid chromatography and glutathione peroxidase activity (GSH-Px) by kinetic method. On the 15th day after supplementation, a statistically significant increase in the percentage of erythroblastic cell line was observed in bone marrow smears. At that time, the increase in GSH-Px activity in the E group was also observed, reaching the value of 165.3 U/gHb, which was statisti- cally significant. The percentage of proerythroblasts (8.23% in group E and 5.02% in group C) differed significantly between groups at the 25th day after supplementation. This study revealed that supplementation of selenium and vitamin E resulted in an increase in the number of erythro- cytes to an average of 13.5 (˟ 10¹²/l) in the experimental group on 25th day with a significant increase in hemoglobin to 193 g/l in the experimental group.