I am trying to find plans for a goat pen you build to fit a truck bed. I've seen them around town, but am never in a position to stop and really examine them. They are usually made with a wood frame and Chain link, and look to be removable. But they are sturdy enough to transport goats in the back of your truck without a tydown or risking them jumping out. Almost like a goat cage. Has anyone seen plans for these, or even knows what I am talking about? Thanks!