Physiological reaction of the blood of black mottle cows to the completion of pregnancy and the beginning of lactation

For the study, completely healthy 47 pregnant cows were selected 3 weeks before the expected calving: the group of first-calf heifers consisted of 22 animals, the group of re-calving animals included 25 animals. The survey was conducted 3 weeks before calving and 3 weeks after calving. Primary heifers after calving showed a decrease in the concentration of glucose, total protein and albumin with a significant increase in the concentrations of malondialdehyde, non-esterified fatty acids and globulin compared with the first study. Recalving cows showed significant decreases in blood glucose, total protein, and albumin, coupled with significant increases in cholesterol and malondialdehyde levels compared to pre-calving levels. In repeatedly calving cows, a significant decrease in non-esterified fatty acids was noted in comparison with calving first-calf cows. The composition of the general hematological profiles of separated first-calf heifers and re-calving cows was characterized in comparison with the level before calving by a significant decrease in the number of erythrocytes and an increase in the level of lymphocytes.