Love it! That is why the Mastiffs make such good guard dogs! They don't attack, they sit on the intruders. That's how they keep things safe! LOL! Beautiful dog! We had one that got stolen. Still look for him, even though it was years ago. Isn't it great to see the 200 pound dog acting so gentle around the chickens, when a little 15 pound mutt could (and probably would!) tear them apart. They are wonderful dogs. You are very lucky to have one. True gentle giants.
I've been trying for years to talk my husband into letting me get an Old English Mastiff but he refuses. He says we can barely afford to feed our teenage son let alone a mastiff on top of him (I call my son and his friends the locusts because if it is standing still I swear they'll eat it). Mastiffs are absolutly wonderful pets, it's amazing how gentle they are..Oh and your chickens are adorable too