If' you are willing to feed them hay all year 'round, yes. Minis are often kept on dry lots; it's usually safer for them than having access to all the pasture they can eat (they can get fat enough to founder on grass, and it's amazingly hard to get excess fat off of a donkey or mule). Are these animals acquainted with each other already? I have a mini mule, and the period of her and the goats getting used to each other was a bit rough on the goats.