EN
The studies were carried out in two stages. The aim of the first stage was to assess the selenium levels in the feed for lambs, as well as in the milk and serum of their dams. The objective of the second stage of studies was to evaluate the impact of using two different doses and sources of selenium (sodium selenite or Se-enriched yeast) on its concentration in lamb serum. The experiment was conducted on 64 lambs divided into four groups, each consisting of 16 animals: group I, the control group - received no additional selenium, group II - received 0.1 mg Se/day/animal (Se-enriched yeast), group III - received 0.2 mg Se/day/animal (Se-enriched yeast), group IV - received 0.2 mg Se/day/animal (Na₂SeO₃). The concentration of Se in feed, milk and serum was determined by means of an atomic absorption spectrometer SpektrAA 220Z with electrothermal atomization and Zeeman background correction (by Varian). Low concentration of selenium in soil, plants and food would suggest a deficiency of this mineral. These results indicate that low Se levels in the serum of lambs generally reflect the level of dietary Se. The results of this study demonstrate that Se from organic sources was markedly more available to lambs than selenium from mineral sources.