Introduction:
In the Czech Republic, there is a deficiency of selenium in sheep due to its low level of occurrence in soil, thus in fodder. Selenium deficiency in these animals can manifest in a number of diseases. Therefore, sheep should be supplemented with preparations containing selenium with vitamin E, because Se is closely related to vitamin E, which plays an important role in the immune system.

Aim:
The aim of the study was to assess the selenium status of selected sheep breeds in the Czech Republic and to determine the effect of selenium and vitamin E supplementation on selected hematological, biochemical and enzymatic blood indicators and on reproductive indicators.

Material and methods:
The research material consisted of sheep, used in the Czech Republic, of three breeds: Šumavka (16), Valaszka (16) and Zwartbles (16). At the 3rd month of gestation, the sheep were injected with sodium selenate with vitamin E. In the blood of sheep, hematological, biochemical and enzymatic parameters were analized, and reproductive indicators of sheep were determined.

Results and discussion:
The concentration of Se in sheep was quite low at the beginning of the experiment (from 0.145 (AVR group) to 0.219 µmol/l (BZR group) and the highest concentration (1.322 µmol/l I BZR group) on the test III. It was shown in experimental groups that with increasing selenium concentration, GSH-Px activity increased from the lowest level of 53.77 (ASR group) to the highes: 222.88 U/gHb (BZR group). In sheep from experimental groups (ASR, AVR, BZR groups) better fertility was obtained, amounting to 96.3%, 95.5%,89.4%, respectively.

Conclusions:
In all groups of sheep there was a selenium deficiency. Supplementation turned out to be an effective method of compensating for its deficiency. The proper selenium status ensured better reproductive indicators for sheep.