QUALITY OF BOVINE PREIMPLANTATION EMBRYOS IN RELATION TO CATTLE BREED

Abstract

The aim of this study was to compare quality of bovine preimplantation embryos recovered from cows of three cattle breeds bred in Slovakia: Holstein (n= 38), Pinzgau (n= 28) and Slovak Pied (n= 53). Total number of embryo cells (DAPI-stained nuclei) and incidence of dead cells (TUNEL-positive nuclei) were counted in total of 563 bovine blastocysts collected from three breeds under the Leica fluorescent microscope. This study was done in 12 experiments performed during seven years. The lowest total number of embryo cells was counted in Pinzgau cattle (107 ± 8.5) and the highest – in Holstein cows (121 ± 5.5), whilst in Slovak Pied cows the embryo cell number was at moderate value (112 ± 6.4). The highest dead cell index (%) was calculated in embryos from Pinzgau cattle (6.22 ± 0.57), whilst Holstein and Slovak Pied embryos showed almost similar values (5.72 ± 0.34 and 5.31 ± 0.49, resp.). However, in both cases these differences among the breeds were statistically insignificant. In conclusion, present study did now reveal an influence of cattle breed on the quality of bovine preimplantation embryos. These findings may have an importance at the realization of genetic resource preservation program in Slovakia.