Jake DeDecker University of Illinois

Publish Date: June 3, 2006

Choice of appropriate group size is an important consideration when designing facilities, particularly for growing pigs (from weaning to slaughter) and for sows that are group housed during gestation. Commercially, pigs are housed in group sizes ranging from individual animals (e.g., sow gestation crates) to, in certain cases, groups of several thousand animals. Small group sizes (around 10 pigs per pen) are used on some operations for growing pigs, particularly those that use litter segregation (keeping whole litters together in discreet groups from weaning to slaughter), although this practice is not widespread. Typical group sizes for commercial production are generally within the range 20 to 30 pigs per group. Recently, there has been increased interest in the use of larger groups for growing pigs. Initially this interest focused on the potential to reduce costs and improve management in larger groups, however, more recently, the development of automatic sorting systems which are based on groups of between 500 and 1000 pigs has added a new dimension to the debate on optimum group sizes.