Anotace:
The aim of this study was to determine and compare the plasma and erythrocyte (RBCs) levels of vitamin E in cows of 3 different categories (2–3 weeks antepartum, 1–3 weeks and 2.5–3 months of lactation) and 1-month-old calves on dairy nutrition. We were interested in the degree of correlation of vitamin E in plasma and RBCs within the individual categories. Blood on EDTA was collected from 61 cows and 12 calves. As a part of the haematological examination, we determined haematocrit (HCT) immediately after the collection. We determined vitamin E from plasma and RBCs by a standard HPLC method. We compared the results of vitamin E in plasma and RBCs and correlated them. The concentration of vitamin E in the plasma and RBCs was 6.98 and 3.45 μmol/l, respectively, in cows 2–3 weeks antepartum; 1–3 weeks of lactation it was 4.98 and 3.34; 2.5–3 months of lactation 11.76 and 2.80 μmol/l; and in the case of calves 12.07 and 6.29 μmol/l. Weak correlations were observed between vitamin E in plasma and the RBC concentrations in the antepartum category R2 = 0.2076; 1–3 weeks of lactation R2 = 0.0369; 2.5–3 months of lactation R2 = 0.2403 and calves on dairy nutrition R2 = 0.4628. Vitamin E concentrations in RBCs were shown to be more stable than in plasma, where the concentrations varied. It is possible that vitamin E in RBCs could tell us more about the longer-term reserves of vitamin E in the organism. The highest concentration of vitamin E in plasma and RBCs, as well as a stronger correlation was found in calves.