I have had American Bulldogs for a lot of years now, and they have been fine with the livestock. I will say that our male is from hog catching lines and if he thought you were in danger with the cattle he would back them down, but he never injured them, and as for the horses he used to play with my stud horse. He would also catch stray dogs, he wouldn't hurt them, just scare the crap out of them. The chickens have been added later in our dogs lives but we have no trouble with them. Maggie my 7 year old female will work cattle like a healer, will run off strays, but will leave any thing she knows belongs alone. She know our cats from the neighbors cats. the only she has ever caught are varmints, opposums, woodchucks and occasionally mice. I love bulldogs, but you must do your homework, I had a male that came to me at 5 monthes old, and he had some issues!! He was super smart, but little things would freak him out. He didn't last long here and had to be euthinized. It was heart breaking, but I don't think he was typical for the breed. These dogs are stubborn, but very smart and required consistancy, which is a must for any breed. Do your homework, make sure you can handle a big, strong willed animal, and definitely find a good breeder that will help you along the way! And honestly I prefer my females, but if you do the spay/nueter route, the gender won't matter, and they make a lot better pet. I know several reputable breeders in MI, but you can call the United Kennel Club and they will help you out, and the people there are really nice.