That's interesting about the raccoon penetrating your barn via the roll-up door. In our case the rollup doors have absolutely no openings. They are rock solid and nearly air tight. I can't imagine an animal getting in when those doors are closed. We went with a commercial grade rollup door that is actually developed for the self-storage units.
Every sliding door I've ever seen was loose and hard to secure. Inconvenient to open from the inside and the way they swing the rock back and forth in wind is disruptive to a calm environment. They always seem to leak water into the barn, too. The rollup doors have none of these issues and when the door is open the door is all wrapped up into a nice tight barrel in the ceiling that's out of the way.
As promised, here's some more pics:
The rollup door in the closed position:
You can also see how we have a ring right in the entrance to the door. So during hay feeding season, we can put hay into that ring and it keeps the hay out of the rain. The cows just walk up to the barn and stick their heads right in and eat. The manure falls onto the porch that they are standing on and we scoop it up daily and put it into a pile for composting.
The barn is 36x36 with 12' on the west side, 12' under the loft, and 12' on the east side. The west side we divided into 3 12x12 stalls, divided with short walls. We use gates in the stall and then we can keep calves, etc, in there. You can also see here how we keep some round bales under the loft. Here is a photo of one of the 12x12 rooms:
And now here's the stanchion where we milk. It has gone through many evolutions and at this point I'm pretty happy with it.
We put feed in the box and the cow walks in and sticks her head through and starts eating. I can then close the right-side bar and drop the wooden block (which is on a hinge) to lock the beam in place. This prevents her from backing out while milking (which has happened before!)
We have a plywood wall there and although it wasn't necessary, we have it because it is on that wall that we hang our milking equipment to dry after we clean it. Since it's a solid wall, none of the animals can mess with the equipment.
The PVC pipe you see goes up to the ceiling and across the barn to where I have the vacuum pump. I situated the pump so far away because I wanted to milk in peace without having the pump roaring right next to me. It's nice to sit and chat with a child or two while milking.
So you can see my little stool there. There is an opening to the stanchion from the stool and I have perfect access to the udder. I could hand milk with ease but the machine sure makes the job faster.