I came up with this SOW Tractor after giving some thought to the issue of having sows highly mobile, highly contained and safe healthy and happy.
It also solves a problem I've seen in pasture management. If you'll notice alot of hay farmers get further and further from the feild edge every Cutting to avoid damaging their cutters.
Running a pig tractor around your feild edges and pasture fringes allows you to make use of otherwise fallow ground harvest soft mass, legumes, and grasses improve sow health and cut down on actual feed inputs. This improves efficiency and effectiveness making it more cost effective to keep breeder sows herd and a boar. It also improves the ground was well.
I use repurposed 71/2" I Beams as my sled runners. (3-4" pipe would work just as well... Aluminum would be better as it would reduce weight)
I built it 10' ID x 24' long. Thus will fit on top of most 16' utility trailers for easy transportation to a different site.
I used 11g 11/4" Square tubing for my upright supports. 3/4" black pipe for my horizontal supports. The side material was 2"x4" x 20' welded horse panels.
I used three 3" drill stem pipes welded to the I Beams 1" off the bottom cut to width to hold the I Beams together. The serve as land levelers and manure spreaders, if you leave it set too long and the SOW turns the ground over.
The roof is 11/2" pipe trusses with re purposed sheet metal screwed down to it using self tapping screws.
Start by squaring up the sled runners, and welding in the drag braces. Build gussets for the front, helping keep it Square and in good shape. Add the uprights on each corner, and at the halfway point. Then install the horizontal braces. I put one support in 6" above the I beam top to account for the nature of hogs to scratch and rub on things.
Then weld the horse panels to the I beam and other supports. I welded every other hole on the panel. The more welded down it is the less damage they can do.
On the back end I built a support shelf to hold a 275g water tank. I use a hose to pipe the water to a drinking nipple. They have clean drinking water at all times.
This pen is very noble with a tractor, but in muddy conditions it can be tough to move. I plan to add repurposed tractor trailer Dolly's to the back corners and weld spindaly to the foot so I can put wheels that Jack down on the back...This will improve mobility in tough conditions.