Initiation timing cannot predict success of superovulation in rhesus monkeys (Macaca mulatto)

Current protocols for Superovulation (SO) of rhesus monkeys are not optimized and outcomes vary considerably. There has been little attempt to predict SO outcome according to the stimulation starting time point (Day of cycle) of the candidate oocyte donors. In the present study, researchers focus on the SO initiation timing and we hypothesized that this factor could be used to select optimal oocyte donor monkeys. Superovulation was initiated on menstrual cycle days 1-4 or 5 of 107 adult female rhesus monkeys then 81 animals were identified as good responders by ultrasonography after 6 days of treatment. Oocytes Pick Up (OPU) was performed by laparoscopic follicular aspiration. The numbers of total oocytes and metaphase II (MII) oocytes from each retrieval were recorded. The results showed that SO begun on days 1-4 or 5 of the menstrual cycle produced similar outcomes indicating that SO initiation in rhesus monkeys can be on days 1-5 of menses. These data showed that SO initiation timing can not be used to predict the SO outcome in. rhesus monkeys.