Behaviour and distribution of fattening pigs in the multi-activity pen

Five groups of fattening pigs were observed in an experimental multi-activity pen with environmental enrichment. The pen measuring 36 m2 included sections containing straw, feed and water connected by two corridors. In addition the pigs had access to straw racks, a shower and biting/levering logs. Social behaviour and spatial distribution of the pigs in the pen sections were recorded as well as the diurnal rhythm of the use of feeders, drinkers and shower. Furthermore, the defecation sites of the pigs were recorded. After the first three trials with 8, 16 and 24 pigs respectively, the pen was supplied with feed trough partitions, straw racks and biting/levering logs. After these changes, two more trials with 24 and 29 pigs, respectively, were tested. During light hours, the pigs were most often observed in the straw and feeder sections. By increasing group size/density, sniffing pen mate decreased (P < 0.01), aggression increased (P < 0.01) and nose to ano-genital increased (P < 0.05). After the alteration of the pen, a significant decrease in aggression was recorded (P < 0.001). Sniffing pen mate, aggression and non-aggressive biting was significantly influenced by the different environment. Most sniffing pen mate was recorded in the water section and the east corridor and most aggression was recorded in the feeder and water sections. Non-aggressive biting was mainly recorded in the straw section and the east corridor. Clinical signs of tail biting were never observed. The pigs were active at feeders, drinkers and shower mainly during the light hours and the activities were clearly bimodal with peaks in the morning and afternoon. The pigs kept the straw and feeder sections free from defecation, which mainly took place in the water section and the corridors close to the water section.