A mare’s gestation is 331-346 days, or approximately 11 months.
A donkey’s gestation can vary between 11 and 14 months, with birth on average at 12 months.
At Gypsy Gold, we utilize mules (a cross between a donkey and a horse) as our recipient mares in our Embryo Transfer Program, and mules don’t usually have the opportunity to carry a foal or give birth. In our experience, you can expect an average gestation of 12 months for our Mule Moms.
For an overview of a foal’s development in utero, watch this brief video:
Below is a gestation table that will allow you to predict the approximate due date of your foal based on the last day the mare was bred.