I was reading about protein today. Trying to decide what to feed my chicks once everyone starts laying. I feed Texas Naturals, and they don't have a "flock" feed. It's either starter, grower or layer. They do have a scratch, which I use, but that is all. From what I've read, the chickens actually do better on a higher protein feed. Most of the layer feed is around 16%. TN's layer is 18%, grower is 22% and starter is 20%. From what I've read, there is really not that much difference in the feed except for the protein content and the calcium in the layer. I'm really considering leaving mine on starter and just supplementing with oyster shell on the side, like I'm doing now.
 
I feed mine about a half a coffee can (13 oz) of scratch every evening. Gives them something to dig for and keeps my dl stirred up. I don't know how much protein your treat has, but usually when you feed them scratch or scraps, it brings the protein down. What protein is the feed your feeding them now?
 
Great idea on the  milk jugs. I had thought about putting frozen water bottles in their waterer to help keep it cool for them.