Scale sorters are a very reliable system and equipment setup that records the weight of each pig as they come across the scale and then sorts them into 1 of 3 pens depending on the weight. Each pen has a designation of either lights, mediums, and heavy pigs, and you have the option to feed a ration that is specific to that weight range of pigs. This also allows the more disadvantaged or smaller pigs to eat with less stress on them from the bigger, more dominant pigs. Sorter pens typically consist of amount 650 pigs per sorter and have a large open common loafing area that they have access to when they are not feeding. The feeding areas are equipped with one-way gates that only give them access to the feeding areas by entering the sorter, but they can exit the feeding area through these various one-way gates.