I am going to perform a study related to the neuroprotective effect of certain herbal compounds and formula in ovariectomized female SD rats through the middle cerebral artery occlusion (MCAo) procedure. I searched the literature to get the appropriate age of female rats for the experimental purpose. I found that there is great variation in the age of rats ranges from 5 weeks to 16 months in the literature. Could anyone please suggest the appropriate age of female SD rats for use in stroke animal model?