I was playing with J in his bassinet (at 11:30 at night, when he really should have been sleeping, but he was wide awake anyway.) He loves to make funny faces and squirm, play with his fingers, etc. At one point during our playtime, I looked at J and said "Hi!!" He looked straight at me and very clearly said "Moo!" I called T and said "Honey, my son is mooing at me. We have a cow baby!" T laughed and started to leave the room. I once again looked at J and said "Hi!!" And I got the same response - a most emphatic "Moo!"
Despite this consistency in response, T insists that it was just a coincidence and that J is not actually a barnyard animal.