Not chickens but had to show off the protectors too. These are brother and sister 10+ yr old American Bulldogs. White is a male, black and white is female. He outweighs her by around 45#s. Although you might not think it, they are great with the flock. I've never had to train them for it and they have never hurt or even chased the birds. I use to have goats too and they have always been very accepting of other animals, well except for coyotes, bobcats, racoons, possums, fischers, gophers, rats and mice.
The chickens and the dogs both look like gentle giants when they are handled by you. But I imagine I would not want to get in between 2 cockerels facing off.