It really depends on the dog. I fully believe every dog needs to learn the "Leave It!" command. Make sure it works for shoes and sandals as well as chickens.
We went to visit friends who had chickens, I took the dogs on leash over to the chickens and let the dogs smell them and told them "Leave it". My irish setter wanted to smell the chickens up (actually loved the back end), but he hates feathers in his mouth so he won't touch the chickens. My english setter, loves to point. He followed his favorite chicken all afternoon, every time it stopped to scratch, he went into a perfect point. Never tried to bite or grab the chicken. A good bird dog is trained to find the birds for you, not kill them, and besides a dog can learn the difference between a chicken and a grouse.