The results of studies on the effect of the use of genetically modified (GM) feedstuffs in poultry nutrition were discussed in the article. The herbicide tolerant soybean and insect resistant maize (Bt) are the most often used as feedstuffs GM plants. In the experiments on poultry and other livestock species the influence of GM feedstuffs on production parameters and the possibility of transfer of transgenic DNA and genetically modified protein to animal tissues have been studied. Results of these experiments indicate that feedstuffs produced from GM plants had no negative effect on performance and exclude the possibility of the presence of biologically active fragments of transgenic DNA in tissues.