In recent studies it was shown that activin A during IVM enhanced postcleavage development of bovine oocytes but not the initial cleavage. The present finding that activin A and/or follistatin did not affect the cleavage rate when activin A and/or follistatin was added to mSOF after fertilization is in agreement with these reports. While the number of morulae and blastocysts was affected by addition of activin A and/or follistatin to medium, the quality of morulae and blastocysts, as determined by evaluation of their cell number, seemed to be similar among the groups (Table 1). Buy Advair Diskus Online
Activin A and follistatin had an effect on blastocyst yield when they were added to culture of bovine embryos prior to the 9- to 16-cell stage. In contrast, addition of either cytokine at the 9-to 16-cell and morula stages did not affect the number of blastocysts. Although addition of activin A to presumptive zygotes resulted in a higher hatching rate of embryos than did no addition or addition of follistatin, this seems to be the result of an increased number of embryos that developed to blastocysts.