I had a few cows and needed a quick cheap shelter, all i had available was some old T Posts, 2X4s a tarp and some pallets. I sat 4 pallets side by side, and drove the t posts into the corners, screwed them together then made a makeshift roof truss high enough for the cows, tied the tarp overhead and filled it with hay. cows did ok that year and I got off cheap. Pallets are usually free and i grab them up wherever I find them. The building plans are in my book along with several other projects.