Hydrangea?

I am a new horse owner. We have 36 acres, 3 mini donkeys, 1 jersey cow, and 1 horse. I really want to plant some hydrangea. I know if eaten in large quantities, it is poisonous. Part of our land is wooded and who knows what all poison plants are out there...!? I know they have a natural instinct to avoid poisonous plants. SO, if there is plenty of other forage and they’re well-fed, they probably wouldn’t even be interested in the hydrangea right?? Would it be safe to plant if not? Thanks!!