I was just reading on another forum of Jack donkeys killing baby lambs. Probably a half dozen different people who have had this occur. I used a female standard donkey with success for many years, so I will confirm that they are less complicated than dogs. Dogs do require more forethought and flexibility. However, their effectiveness cannot be compared. They way we looked at it, is our sheep are very valuable. The death of a single lamb would cost us hundreds of dollars. Or more. A pack of coyotes, stray dogs or a single mountain lion can kill a dozen sheep in a night. I hear so many say, "We never had problems with predators before." And then they have an attack and are devastated, financially and emotionally.