Donkeys are sometimes used in herds as additional protectors of calves from predators (e.g., coyotes). Our most recent trial was less than successful... Jack, was less of a protector and quickly became the wimpiest one in the group (scared of the cows). These two donkeys on the left are on one of the farms we rent. We may give it another shot, but for now, they are more for fun than purpose. Ace was a little intimidated and stayed in the side-by-side with me.