Hi, most of this is on previous posts, go to food standards agency website for food chain forms, load pigs the night before is a must, they will be fine in the trailer overnight. when you get them back depends on the slaughterhouse, if ours go in on mon or tues you normally get them back on friday, do you know how you want the pig butchered? marking on pigs must be either slap mark or metal tags,most slaughterhouses dont like plastic ones as they will not survive the process. as long as their reasonably clean dont worry about mud on legs, rub it off with some straw if its to bad. best of luck neil