A semi-outdoor system may provide low cost housing for non lactating sows in high rainfall regions where full outdoor systems are impossible. Two other means of minimising capital costs are dynamic grouping and communal floor feeding. These elements were incorporated into a pilot study using a dynamic group of 24 sows with a replacement rate of 5 sows every 2 weeks. One group of new entrants received so much aggression in the enclosed feeding arena that they subsequently refused to enter voluntarily and failed to integrate with residents in the straw-bedded house, preferring to nest as a sub group at the furthest end of the outdoor paddock. This failure may have been due to the enclosed feeding arrangements and/or to the size and replacement rate of the dynamic group. Experience with the pilot study lead to the experiment reported here in which two feeding systems were compared.