The objectives of large group housing (LGH) are reduce labour, increase pigs marketed in the ideal weight range, reduce overall production costs, and enhance animal welfare. The most typical system is a fully slatted floor. Positives in regard to facilities include pigs having greater selection of a comfort zone; avoid aggression, better observation, and more. Negatives include lack of knowledge in airflow and dunging patterns. Water may need to be added to certain areas to improve the flow in the pits and ammonia could be a problem with fully slatted floors. Positives in regard to equipment include less penning, reduced feed system costs, reduced water system delivery cost and maintenance, reduced cost of ventilation equipment. Negatives include the addition of more equipment requiring more maintenance. Event sort is the sorting of a large group at one time for one event, while continuous sort will sort pigs based on weight on a continuous basis. Equipment used in sorting includes a return gate, feeder, sorter (needs to be strong, dependable, easy to operate and clean, provide protection, and must be placed well), and drinkers. Positives for building cost include less pen partitions, less unusable floor space associated with dividers, reduced cost of floor space as alleys, and more. Negatives include construction costs of $25-30 more per pig space for fully slatted over partially slatted design and the cost of an automatic sorter. Positives for labour include reduced time spent manually sorting and weighing, reduced time to check feeders and drinkers, reduced washing time, and more. Negatives include maintenance with the pigs in the pen, pig swarms, working with individual pigs, removing dead pigs, and more. Positives for operating costs include weighing, sorting, washing, reduced wash water volume, feed restriction, reduced maintenance, and more. Negatives include possible maintenance increase if sorter is faulty. Performance is increased when more pigs can hit the core grid target due to the auto sort. Positives for health status include fewer partitions for disease to hide, less fighting due to more space, and a hospital pen. Negatives include increased risk of disease spreading, vaccination is more difficult, daily health check needs to be more intense, and more. Animal welfare advantages include less aggression/fighting and it looks good in the eyes of the public. Injured animals may be more difficult to find though. Pork quality is increased due to less stress and easier management.