Investigation of Bull Effect on in vitro Embryo Production

The aim of the study was to show whether there were some differences among 9 Holstein bulls and within their replications on their ability of in vitro fertilization for in vitro embryo production as cleavage and coming into the blastocyst stage. Semen collected and frozen from nine Holstein bulls with satisfactory in vivo fertilization capabilities for artificial insemination was used for in vitro fertilization. Direct washing method by Brackett and Oliphant medium and 5 or 6 h incubation period were used for in vitro fertilization. Charles Rosenkrans medium was used for in vitro embryo culture. An atmosphere with a higher than 95% relative humidity, 39 degrees C, 5% CO2 and was used for all in vitro embryo production processes. Totally 2519 A and B quality oocytes were treated for in vitro embryo production. As a result statistically significant (P<0.05) variation was found for cleavage and blastocyst development among bulls. However there was no significant difference (P>0.05) between the replications for each bull as cleavage and coming into blastocyst stage. The results showed varied capabilities of bulls for in vitro fertilization and embryo production and male factor can affect success of in vitro embryo production.