Influence of breed on the quality of in vivo produced embryos from Boran and Holstein Friesian cross dairy breed in Ethiopia

The variation of the dairy breed can determine the success of bovine embryo transfer by influencing the quantity and quality of in vivo embryo production. In this experiment, output and quality of in vivo produced embryos using semen of progeny tested Holstein Friesian (HF) sire in Boran and HF*Boran F1 cross cows, and semen from purebred Boran sire in HF*Boran F1 cross and Boran cows were evaluated. Boran (n=18) and HF*Boran cross (n=18) breed donor dams were superovulated using a previously optimized follicular  stimulating hormone (FSH) (Pluset®) dose regimen: 650 IU for HF*Boran cross and 250 IU for Boran breeds. Each cow was flushed on  Day-7 post insemination and embryos were evaluated for their developmental stages and quality. Superovulatory response rates were 88.9% and 83.3%, respectively, for Boran and HF*Boran with no significant (P>0.05) breed differences. Total recovery rates were relatively lower (56.5%) in Boran compared to in HF*Boran (67.4%). The mean (±SE) embryo flush outputs were 6.5±0.8 for Boran and 6.9±0.7 forHF*Boran with no significant breed difference. Recovery of a transferrable embryo was significantly higher (68.0%; P<0.05) in HF*Boran dam inseminated with HF sire semen. Boran cows yielded a significantly higher (P<0.05) proportion of unfertilized ovum (57.6 %)  irrespective of the sire breeds. Comparatively, a higher number of degenerated embryos were produced by HF*Boran cows. This study demonstrated that the presence of breed-related differences in both the quality and quantity of in vivo produced Bovine embryos.