Building a corral, part 3 of 5, rails and gate framing

Completed all of the rails today for the fence. So far it's taken 4.5 man days of labor to get this far. Next on the list are the man gates (2 of those) loading chute gate, main entrance gate, and crowding gate. The chute pictured below is to the left in this picture.
This chute is the loading/working chute. At the end of it there will be a Y and one direction goes to the loading ramp, the other to the squeeze chute. It'll be faced with plywood so that the cattle aren't distracted or caused to balk by stuff outside the chute. Because this chute is 6' tall, there will be a 2' tall catwalk along the right hand side of this picture, on the inside of the corral.

I'm probably going to add two blocking gates to this chute so that I can both stop the cows from backing up, and so that I can control how many cows I have going in at a time. One blocking gate just in front of the squeeze chute, with a gate on the side will allow me to empty the chute to get to a cow that I'd like to work on. An example might be having 3 cows in the chute. You want to get rid of the first two to get to the one who needs attention. A blocking gate allows you to stop all of the cows in the chute from rushing the gate at once.

The bottom of this chute, and part of the entrance, will get a 4" concrete slab to complete the structure. Since it's relatively dry now we can wait a month or two to pour the slab with no harm done. I'm choosing to put a slab under this part of the structure because I'm sure that it'll turn into hip-deep mud if I don't.

It blends right in. Next steps:

#4) 6 gates to be constructed/attached

#5) Adjustable loading ramp