i have two very cute and very protective miniature donkeys. they are born with a natural dislike of dogs. so if you have a pasture in which you have chickens... look into a miniature donkey. they will keep grass down.. and keep dogs and other predators out of the pasture. but be careful the donkeys are very curious and sometimes can be jealous. one of mine will try to get your attention by nibbling on my hair,shirt,leg,arm,or fingers. haha