I've seen many requests of the different ways to farrow pigs other then the traditional crate so I decided to show some pics of our design.
  Each pen is 10 feet long, including a 2 ft wide creep or hoover, and 5 feet wide. The pens were built out of 1 inch square tube. The filler on the side panels is 1/2 solid round. The creep and the front panels are covered with 3/8 plywood. The pens are made up of four panels held together by 1/2 inch vertical rods. When the piglets are 7-10 days old or when they start jumping over the 12 inch high front the pens are easily disassembled and removed. There is a door on this barn that allows the sows to go outside to eat and drink. We covered the south side of the barn, which has an opening big enough to get a tractor in for cleaning, with clear plastic to let the sun shine in during the day and doors that are closed at night. This solar passive heating has seem to be working as this barn has no supplemental heat other then the heat lamps in the creeps.
  The first farrowing in this barn, January 2006, we  weaned 11 pigs per sow. The outside temperature was 35-40 during the days and 25 at night. The first pig we noticed that learned how to jump out was 10 days old. The straw or wet spots had to be cleaned out of each pen every 5 to7 days and replaced with fresh straw or you could start to smell an ammonia odor.