Housing immature domestic pigs in large social groups: implications for social organisation in a hierarchical society

摘要: Abstract Immature domestic pigs are increasingly housed in large social groups (>50 pigs) without an understanding of how they adapt to these conditions. At a conventional group size (typically 10–30 animals), exhibit dominance relationships which frequently established using physical assessments strength and fighting ability may include the use aggressive behaviour. The also rely on individual identification members recall reinforcement previous fight outcomes. This paper reviews implications for establishment long-term maintenance immature pigs. Evidence suggests that, groups, less reliance is placed aggression during immediate post-mixing phase than would be expected if same proportion both small groups. occurred despite distinguish between pen mates non-pen mates. energetic costs pig establishing with given likely increase size. It considered whether elevated place ceiling number fights can engage or able assess passive means thereby reduce fight. probable that combination two routes responsible limitation observed. Sub-grouping behaviour, investigated poultry appears not adopted by response There need further fundamental research investigate way behaviourally at level several potentially fruitful investigations suggested.