Training our rottweiler not to eat chickens was not too hard. We would frequently make her lie down and put the chickens on top of her so she would come to realize they were at the top of the pack.

Also, every time she even looked at the chickens she got a stern "No!" or "leave it.' After a couple of weeks of that she figured out that they are off limits. Now the chickens walk all around her and she just ignores them.