Weaning causes social stress for the piglet, which includes separation from the sow and being mixed into pens with non-litter mates (13). Separation from the dam also prevents piglets from satisfying their drive to suckle teats, and may promote manipulations of other pen-mates in an attempt to satisfy this drive to suckle. Thus, welfare of both performers and receivers of the abnormal behavior may be jeopardized and this has the potential to adversely affect production.