i still remember the little Brama Bull that tried it's best to be my friend. It licked my shoes and hands and nuzzled me. I've encountered numerous cows and horses of course and pretty much any animal...
If coyotes are a problem in your area any vulnerable livestock will need some protection. My brother adopted a Great Pyrenees to keep his goats safe. I'm sure not an expert, but I believe donkeys can be used to guard livestock, but in general it's full sized ones that are recommended. Taking on coyotes might be a bit much for a small one?