The pig carrier for the tractor

One of the things that I've built that I've been really happy with is my pig carrier.  It's a 6'x6' metal box that hooks to the 3 point hitch on the back of the tractor.  When it's up it has about 18" of ground clearance, and will lower all the way to the ground.  The floor is expanded metal, and that's turned out to be really handy -- stuff drains through it, and when you put a pig or pigs into it, and lift it off the ground, the pigs stand still and stare at the ground.  "whoa!  I am floating!  wow!!" so they don't try to jump out. 

I've got one of the arms on my three point a little high here, which is why it looks a little off, but you can see the door.

What I'd change if I were to build another one
 If I were to change anything, I'd make the top rail about a foot higher (it's about 36" now) and I'd make it out of pipe instead of angle iron.  When I'm using this I'm standing at the side and leaning over many times, and some smooth round pipe would be better there.  I'd also make the top rail go all the way around.  It hasn't happened very often, but every now and then a pig will get motivated enough to jump out.  a 4' rail would make that more difficult.  I'd also change the latch.  The barrel bolt I've got is too difficult to close when you're using the door to move.  Some sort of flat stock that closes into a V shaped receiever, so that if the door is open the latch will help close it as it goes down into the V would be good.

A second thing that I'd do is to make the bottom of the cage on the tractor side a big piece of angle iron like the top rail is (see pic below)  I've found myself using this metal box to grade my road or smooth wood chips or whatever, and I've pushed in the expanded metal at the bottom a couple of times.  a piece of angle iron there would make it possible to do that and not damage the box.  It also makes sure that you don't damage it if you forget to lift it before you drive off.  

The top link hookup is a couple of pieces of flat stock, about 1.75" apart, with a hole drilled through them.  It's welded to the botton of the angle iron that runs across the top of the cage on the tractor side. 

The bottom links are a pair of 3pt bolts, bolted onto the angle iron frame of the box. 

This setup can lift 3 400lb hogs with ease.  So when I need to move sows from here to there I take the tractor out into the field with a couple of 36" high hog panels, herd the pigs into the carrier, lift them and drive away.