WOW! There's a ton of info there FC. And THANKS for that, lots to ponder.
There won't be any litter turning once they're out on pasture, they'll be moved daily maybe twice depending on their output. Part of my continuing pasture/hay field improvement plan. At 2 sq/ft per bird the 8x12 comes to 47 birds and with diligent methods I feel good about running 50. Joel Salatin runs 75 in his 10x12s , which should only have 60 according to convention.
I don't know for sure how many birds we'll run this first go. It depends on if a few friends want to get in on the action there. As long as production costs are covered I'm good with doing the work. Any friends that want birds will need to be on hand for processing. I'll farm em, but the owners need to help out with the final destination or pay more. My bride and I can mange our own birds, but I like the skinning idea too as I already plan to part out a bunch of em. We have 2 small chest freezers and will get a larger one if needed.
So far locally procured organic/non gmo feed is going to put us at around $10 per bird, still researching that.
There are several cattle panel tractor ideas on YT and I'm handy with tools (I hand built, wired and plumbed the cabin we're moving into) so that's a non issue and my 35HP LS tractor will handle the heavy lifting as well as mowing ahead of the birds as needed. I'll have tarps to cover the tractor, so our food will be protected from the elements and YES, I was thinking of an antidigger apron too. Our worst enemy will likely be coons and opossums as well as coyotes. There'll be motion activated lights and noise makers for those bump in the nighters and failing that, high velocity lead poisoning will do the job.
Our first run will have them high and dry, actually moving them around the kitchen garden area this year. If all goes well I'll run them through my back meadow next year to improve the grass for mulch hay.
For now we're just watching 14"+ of snow melt and dreaming about fresh air on our land with nothing but the beeze, birds and a neighbor's roosters (and Guineas) for noises.
That sounds dreamy, all that nice land and a cabin to boot!!! I'm totally jealous!
We have raccoons, foxes, cats, possums, and my apron works great.
I had totally planned for my husband to help me process the chickens, and for my kids to help, and none of that happened. My husband was not around at all, and my kids made everything take twice as long (I love them, but can only do that so many times, so I taught them once or twice and left it at that). Always have a backup plan for processing if your original plan falls through.
If you're committed to moving them twice a day, you'll probably be fine with the poo, and it will be good for the birds to get exercise. It's unreal how much poo they make! Salatin is an expert, so what he says I'm sure will work. I like more space, because I'm in there a fair bit as well doing chores and don't want to step on chickens, and for poop load due to being stationary.
One warning for tight quarters - if you pull feed and reintroduce in the morning they will mob the feeder. I was using a round 25 lb gravity feeder in my brooder, and at 3-4 wks they were slicing through each others' rear skin to the muscle trying to climb over each other to get to the feed in the morning. I had to introduce a long chick trough feeder on one end of the brooder, and while they were stampeding that way I'd introduce the 25 lb round feeder on the other end, and pull the trough feeder after about 15 minutes or so, when morning rush had slowed down. I switched them over to the covered run, and a literal gutter feeder, so every bird had 1 ft of space and then some, and there were no more sliced up rear ends because they weren't competing so badly. Guess I'm trying to say, make sure every bird has a space at the feeder the size of their body width at all times, to avoid injury. They will not hang back and share like eggers will depending on pecking order. It's every chicken for their voracious self immediately.
They also don't get out of the way of anything. If you don't physically move them, it's easy to squish a chick with the food or water, depending on how it's mounted/hung. And once they get big, about 7-9 weeks, I'd have someone keep an eye on them as you move them with the tractor. If they get flipped on their backs, they may not be able to flip themselves back over. I had one get trapped on her back because she tripped on something and fell over trying to reach the water. Luckily I was there to rescue her or that would have been the end. Also research green muscle disease, and get them used to your tractor early, so they don't develop that as a result of hearing your tractor.
Not sure how you plan to water, but I used two 5 gallon buckets with 4 horizontal nipples each, and that was good for 21 CX. I'd fill it every other day, and in case of leaks, they had a backup water source. If you do those type waterers, put a vent hole so they can't form a vacuum seal and stop giving water. If you use the horizontal nipples on PVC pipe, make sure you have a way to clean things and introduce medicine like CORID into the water if needed.
Sounds like you are off to a great start! Have fun with it!!!