[Creation of a European bison sperm cryobank as a method for preserving the genetic polymorphism of the species].

Sperm was taken from one alive (by electroejaculation) and two dead (from epididymis tissue) wisent males, and was conserved by the method similar to that used to freeze sperm from cattle. Spermatozoon mobility and acrosome conditions underwent no noticeable changes when kept under preservation. Eight cows were fertilized with the sperm which had been kept in liquid nitrogen for three years. Four of them had hybrid calves. We also made genetic analysis for bull-donors: on blood groups, isoenzyme systems and the protein spectrum of blood serum and muscle tissue. The analysis revealed the rare antigene H' in one of the bulls and polymorphism in two isoenzyme systems in the other one. The results of the analysis proved that these animals can make valuable contribution to the developing genetic cryobank.