Train them not to kill your chickens, and then take them home. I know many dogs, including one of my own, who were trained to stop killing chickens by having a dead chicken tied about his neck with a piece of rope. The dogs absolutely hate having a dead thing attached to them and they freak out. It only has to be done once for one full day and they'll never touch a chicken again... at least not one of yours if you're the one that ties it to them.
Then again, this may not be a practical thing to do if you don't have an area to pen the dogs in while they are "being trained". You certainly wouldn't want them to run home with chickens tied about their necks, now would you?