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Sow housing is a controversial issue in the swine industry.The conventional confinement housing system for sows, such as gestation stalls and farrowing crates have been used in western countries for more than 30 years.Despite the advantages of confinement sow housing systems, concerns over sow welfare due to restriction of movement have resulted in gestation stalls being banned in the European Union and several states in the U.S.In addition, the largest pork producers, some chain restaurants and grocery stores in the U.S.and Canada have announced to phase out gestation stalls in favor of group housing systems.However,group-housing systems for gestating sows present challenges of controlling individual feed intake and aggression at mixing.To control individual feed intake, several feeding systems, such as electronic sow feeders,free access stalls, and trickle feeding systems have been developed for group-housed gestating sows.Each feeding system has advantages and disadvantages in terms of controlling individual feed intake, efficient use of floor space, and facility investment.Regardless of the type of feeding facility chosen, all group-housing systems subject sows to aggression at mixing, which compromises the welfare and performance of sows.Management strategies to minimize aggression among sows include nutritional, social and physical interventions.Scientists at the University of Minnesota investigated whether these management strategies can reduce aggression among sows.Our data indicate that group-housing systems can improve the welfare of sows only when individual feed intake of sows is controlled and aggression among sows is minimized.The selection of a proper feeding system, such as electronic sow feeders, can help control individual feed intake so that sows can maintain desired body condition.Management options, such as mixing sows after pregnancy confirmation,keeping sows in static groups, housing young sows separately from mature sows, and providing open stalls as hiding places during the initial mixing period, can help reduce aggression among sows.So, the welfare and performance of group-housed gestating sows can be safeguarded by proper management strategies and housing facilities.