Recently, sow-activated electronic concentrate dispensers allowing dry sows to be group-housed and individually fed have been seriously considered as an alternative to the close confinement of pregnant sows. For the system to be economic, each feeding unit needs to be used to its maximum potential, while at the same time considering the well-being of the animals.

Previous work has established that levels of aggression may be minimised within a set group size and the maximum number of sows per feeder may be increased to over 30 by feeding only once per day on this system (Lambert et al., 1985). With groups of this size, the practical aspects of large group management need to be considered.