Electronic sow feeding (ESF) systems allow group housing of sows with individual feed allocation, significantly improving welfare over individual stall housing.
Group sow housing with ESF is a major welfare advance over individual stalls because it allows natural social interaction, exercise, and exploratory behaviour. However, poorly designed ESF systems create high-competition queuing and aggression around feeders. Subordinate sows may be prevented from accessing their full ration. Pen design including entry and exit race length, number of ESF units, and pen complexity affects competition intensity and subordinate sow welfare outcomes. Well-designed ESF group housing provides excellent welfare for the majority of sows.