EN
The objective of the study was to evaluate the efficacy of two selenium sources (sodium selenite and Se enriched yeast) in terms of its concentration in the liver, heart, kidneys and skeletal muscles of lambs. The experiment was conducted on 48 lambs divided into 3 groups, each consisting of 16 animals: group I (the control group) - received no additional selenium, group II received 0.2 mg Se/day/animal (Se enriched yeast) for 1 month, group III - received 0.2 mg Se/day/animal (Na₂SeO₃) for 1 month. Tissue samples for analyses were collected after slaughter, after 2 and 4 weeks of the oral administration of selenium and in the 6th and 8th weeks of treatment (after the end of selenium supplementation). Selenium was determined in the samples after microwave mineralization using the atomic absorption spectrometer SpektrAA 220Z with electrothermal atomization and Zeeman background correction, Varian. The research results revealed that selenium supplement has increased selenium concentration in lamb tissues and organs. The best performance was observed in the lamb group fed the yeast selenium improved diet. The highest selenium level was determined in lamb kidneys and liver, while the lowest in the heart. The selenium content in lamb tissues and organs recorded in the final stage of the experiment indicated a deficit of this element in the organism. Therefore, it is recommended to improve lamb diet with a selenium dose established on the basis of the selenium status of the animal’s organism as well as to determine selenium content in the sources of this element.