ABSTRACT:Peat is an easily available natural material and a source of biologically active substances widely used, not only in agriculture but in human and animal medicine as well. In recent years, interest in the use of peat as a feed supplement has increased, particularly due to its capability to prevent enteric diseases and to stimulate growth in piglets and pigs. The purpose of this review was to compare the advantages and risks associated with the use of peat for animal nutrition based on the literature available. Beneficial effects of various peat preparations on digestion, growth and the immune systems of animals as well as the absorbent and detoxifying capabilities are associated with the high content of favourable humic substances. One disadvantage of using peat preparations is the considerable diversity of the various types of peat caused by different biological, chemical and geological conditions during formation. Biological activity of various peat preparations is associated not only with fluctuations in the chemical compositions, but also with different application techniques. Based on the existing studies, it is unclear which application technique is most effective for respective animal species. Further studies should be conducted to elucidate the problem, with the inclusion of farm animals. One potential risk of peat feeding is the possibility of primary or secondary mycobacterial contamination. As long as feed rations are supplemented with peat preparations, it is essential to minimise the potential contamination risk during mining, processing and storage.