Superovulation in cows synchronized with two different progesterone+oestradiol protocols

Abstract. A total of 26 Brown Swiss cows were used to compare the synchronization and superovulatory response of follicle stimulating hormone treated cows that were synchronized with progesterone+oestradiol valerate or benzoate. Control cows (n = 8) were superstimulated with follicle stimulating hormone using twice daily injections with decreasing doses from day 10–13 after determined reference oestrus. Cows in treatment groups were received either ear implant (n = 9) containing norgestomet+oestradiol valerate or progesterone releasing intravaginal device (n = 9) containing progesterone+oestradiol benzoate, at random stage of the oestrus cycle, for 9 days. Seven days after the implant and progesterone releasing intravaginal device insertion, follicle stimulating hormone was injected as described in the control group. There was no significant difference between the groups for superovulation responses. In conclusion, both protocols synchronized the oestrus cycle in follicle stimulating hormone treated cows and, any of the protocols evaluated in this study can be used as a pretreatment for superstimulation started on the seventh day of the implant or progesterone releasing intravaginal device insertion in Brown Swiss cows.