In addition to the traditional Open Day, May 1, 2023 was also the day of the inclusion of the new exhibition "European Bison and its interspecies hybridization with cattle" in the hippological exposition of the National Stud of Topoľčianky. Despite the fact that a bison and a horse are different animal species, the history of bison breeding in Slovakia is also connected with the history of the stud farm in Topoľčianky. Their joint history began to be written in 1981. In cooperation with the current Department of Genetics and Breeding Biology of the Slovak University of Agriculture in Nitra and the support of the Ministries of Culture, Education and Agriculture of the Slovak Republic and the State Forests of Topoľčianky, an experimental and breeding project was established, anchored in the research task "Study of biological and genetic issues of effective use of bison crossbreeding with cattle". The project manager was prof. Ing. Jozef Kliment, DrSc. and the co-researcher was prof. MVDr. Pavel Šťastný, PhD., who personally participated in the presentation of the new exhibition. The joint hard work was rewarded with positive results, and thus for the first time in history, an interspecies crossing of a Slovak mottled bull with a bison was achieved, which gave birth to healthy offspring. Despite the great response from the professional public, the experimental farm ended its operation in 1988. It is all the more important to remember this exhibition, which was also ground-breaking in the world in the field of interspecies hybridization.