My first year with pigs is going well. I have them in a 20 x 30 foot pen that I made with strong oak pallets. Works Great! Although I wouldn't recommend pine, or spruce pallets, they just would'nt hold up. This is going to be a wonderful garden plot next year. I would like to install an electric fence and pasture my next 6 pigs. I want them to clear some tag alder, dogwood,and willow that has taken over what was once a pasture. I would like to know what size of plot do I need to fence off to keep them well fed, but also to have just enough so that they kill off the tag alder and dogwood. Thanks in advance.