Cackle has Silver Laced Orpingtons, which the roundness, size, and white legs of this bird indicate is what it is. I also believe based on the general coloration that this could be a male, but it's hard to tell with the state that its feathers are in. No, that is not 'frizzle' on its back, that poor feathering is evidence of feather picking or poor nutrition. Your birds all look to be in pretty rough shape in these pictures. Are you sure you've provided them with adequate space? How big is their coop and run, and how many birds live in it? What exactly are you feeding them and how much? Do you have a feeder or is the feed on the floor visible in the pictures how you've been providing their food?