The study housed 120 pregnant sows from Day 29 of pregnancy to 1 week before parturition either in groups of 10 with trickle feeding (TRICKLE) or in groups of 20 with an unprotected electronic sow feeding (FITMIX). The study recorded aggressive interaction on 11 nonconsecutive days. Frequency of aggressive interactions was higher in FITMIX (p <.05); yet, intense physical contact was unusual in both systems (3% of the total interactions). Conflicts in FITMIX centered largely on the feeder (83% vs. 23% for FITMIX and TRICKLE, respectively [p <.05]); in TRICKLE, they occurred mainly in the resting area (13% vs. 48% for FITMIX and TRICKLE, respectively [p <.05]). Forty-six percent of the FITMIX sows (mostly gilts and subordinates) needed assistance to adapt to the feeding system. Eventually, 8.3% of the FITMIX sows failed to adapt and had to be removed. In conclusion, although aggressive interactions were mainly of low intensity, sequential feeding appeared to make FITMIX a more competitive feeding system. © Taylor & Francis Group, LLC.