After seeing the thread on loading heifers, I'll share my thoughts and experience on loading facilities:
Loading pen and chutes should be about 6 1/2 feet high. The welded 1/4 rod corral panels which come in 16 foot lengths are fine, but must be topped by 2 x 6 boards to bring height up to 6 feet. I had sone 1 1/2 oak boards sawed which work well as long as they are knot free boards. The chute should be made of all boards. Making a chute out of plywood so that the cows can't see through cracks should be ideal, haven't tried it. Loading from a barn with the trailer on the outside works fine, when the cows see the outside light they head for it thinking they are getting out. The chute should have a bend or bends in it so the cows can't see the end until they have been going some distance so they think the path is clear until it is too late. The chute should have a sorting gate in it so you can divert cows you don't want to load.
Boards in the pen should be fastened to posts with lag bolts at least 5/16 in diameter. Length depends on thickness of board and how good a fit to the post can be arranged. It would be nice to take posts to sawmill and get one side sawed smooth. Commercial treated posts are smooth enough. If you cut your own posts, the kind of suitable trees varies over different parts of the country and I won't try to list them.
Pen should be located at a traffic way between 2 pastures, ideally, so the cows will be used to passing through the pen. Also ideal would be to
have the pen large enough to hold all the herd with a smaller loading pen and crowding gate.
There are 3 basic ways to get cows to come into
a pen, feed, salt, and water. Getting the cows used to being fed with no excitement gets most cows to come in the pen. Placing a salt block in the pen, then removing it for a few days, then putting it back in a day or two before trying to load helps. If the only source of water is in the pen, sooner or later they will have to come to it.
One final trick: Have 2 entrances to the pen, with one entrance in the loading chute with a gate that can be left open or closed to the outside with an opening left to the rest of the chute. When the cows see you coming to clost the main gate, they will try to leave by the gate in the chute which is now closed and sending them to the trailer. In extreme cases, park the trailer at the loading chute a few days ahead to get them used to it being there. I would unhook the truck, not trusting the cows not to damage the truck. It can be interesting to hook the truck back up though.
KEH