The resource requirements, such as feeding space, of pigs housed in large groups are poorly understood. The feed intake requirement may be unaffected by group size, but the ability to gain access to the feeders may be influenced by the changed social environment. The observation of pigs feeding may stimulate others to feed also. In large groups, the number of pigs attempting to feed simultaneously could lead to increased competition for access to the feeders (Spoolder et al., 1999). Consequently, the suitability of two feeder space requirements, derived from UK recommendations, for pigs housed at different groups sizes was investigated.