If it was me I'd use the pallets like you intend for a large compost pile/containment and the blue barrel (and yes I mention this in almost every compost or chicken feed thread I'm subscribed to) would be come a Black Soldier Fly bin. With the 100 chickens you have you could use some of that waste along with a little of your garden/kitchen waste and crank out pounds of free feed for the chickens. As others have said don't use any meat in the compost pile but you can put those scraps into a BSF bin and the little larvae will eat it up. There may be a small amount of time (a few days) where the meat scraps can attract regular house flies. Don't worry much about them since once the BSF larvae are on point they'll not only eat the maggots (I've watched them do this in my bin) but they'll also produce a pheromone that will drive out any flying insect other than the BSF Oh and dog/cat poo is a huge no-no in a compost pile or BSF bin. My guess is that in TN you have BSF flying around that you've just never noticed. Once established you'll also have them in the regular compost bin and trust me in that they turn waste into amazing soil amendments in a hurry. You'll probably also end up with red worms in the compost on the ground and they'll amend anything that the BSFs don't so soon you'll have rich dark soil for your garden and feed for the chickens all made out of stuff that most folks just toss into the trash.
Ok I'll stop singing praises to the Black Soldier Fly now.
