Chromosomal instability of purebred and crossbred dairy cows

The article presents the results of research on karyotype characteristics variability in purebred and crossbred dairy cows. material for was peripheral blood samples firstborn cows Ukrainian red-spotted black-spotted breeds, as well obtained from crossing with Montbeliard bulls (DG “Nyva” SE Institute Animal Breeding Genetics named after M. V. Zubets NAAS. Preparation cytogenetic preparations, analysis morphology, identification classification chromosome aberrations were carried out according to generally accepted methods. We performed cell Axiostar plus microscope (Carl Zeiss, Germany) under immersion magnification 1000 times took microphotographs. In all studies, frequency aberrant metaphases spectrum chromosomal determined parameters instability. following signs taken into account: aneuploid polyploid cells, cells premature separation centromeric regions chromosomes (CRC), structural (breaks, fragments associations non-homologous chromosomes). As a result karyotypes origin, it established that proportion diploid norm is average 85%. remaining almost 15% are somatic numerical abnormalities. Crossbred have significantly higher frequencies (P<0.001) (one half times), (by 27%), 20%) than breeds. 15–20% more containing breaks also found firstborns. study indicate greater instability compared One reasons this phenomenon may be influence breeding methods, particular crossbreeding.