Our burro (a donkey with markings that look like a cross when viewed from above, hence the preferred beast of burden for Christian missionaries) was wild for the first couple years of her life. We got her through the wild donkey rescue program when the president ok'd their wholesale slaughter by ranchers in the southwest. She is a wonderful sentry for the sheep and will lead them away from predators, only attacking if cornered. In the spring she sheds her fluffy brown coat and gets a sleek short coat. As long as there are plenty of rocks around she will chip off overgrowth of her hooves. We haven't had to trim her hooves since the first time we got her about 7 years ago. She shows affection by nipping you on the calf. I'm sure it's gentle to her, and only causes bruising, but if she's mad at something, she can kick and break bones real fast. She can aim a single hoof too. We had a boar who was a bit overzealous about wanting to try to mount her. He'd run and jump and of course only succeed in annoying her. She'd then turn her head around, raise one foot and zap him right between the eyes. He'd run off squealing for a few minutes and then the cycle would repeat until she was out of heat and he lost interest. She will eat just about everything. The children gave her pepperoni pizza, but her favorite treat is the trimmings and tops of pineapple and then after that, any fruit or fruit tree leaves. They browse as well as graze. When she brays for supper time treats, you can easily hear her from a half mile away. Her sounds travel better than the dogs, sheep or pigs. the above is certainly right about dustbaths. Seeing her roll on her back is rather amusing.
Historically, wagon trains with burros through grassland could make 20 miles per day when they took time to let them graze.