The cytogenetic control system of bulls sent to AI stations has been in use in Poland since 1989 and it is aimed to eliminate from breeding the bulls and semen of sires affected by chromosome abnormalities, with provision for extension of the studies with family material. In the years 1989-2002 451 animals of Polish Red cattle were cytogenetically investigated and in this population four cases of 60,XX/60,XY leucocyte chimerism and three cases of 1;29 Robertsonian translocation had been found. The aberration carriers were not related. The next four cases of 1;29 Robertsonian translocation, recently diagnosed (2003) in a herd of Polish Red cattle, suggest the need for cytogenetic monitoring of genetic reserve breeds of cattle that would also account for females.