I have built a rather nifty device that no pig has yet managed to destroy or kick over. Mine is sized for two normal black buckets. Bang 6 50x50 pegs deep into the ground, at least 300 mm, with about 400 mm above ground. Then attach horizontal strips of wood to the pegs all round to keep the rectangle in place, and two horizontal cross pieces in the middle to keep each bucket space separate. The trick is to put the top piece of wood about one incher higher than the top of your bucket, and the bottom piece should be wide enough and placed so they cant get their noses under the bucket. The size of each square bucket space is about one inch bigger than the widest diameter of the top of the bucket. Now you have a double bucket sized, opened top box fixed into the ground. I can just pick up each bucket and refill it, and they cannot empty them the usual way! It has saved a lot of time, and also a lot of mud as the water is not forever being tipped out.