Table 1.

Ethogram of behavioral categories and their respective definitions (adapted from Statham et al., 2011; Rhim, 2012)

Behavior	Description
Inactive	Motionless and sleeping
Chewing	Chewing (not on another pig) with its head raised and away from the feeder
Locomotion	Any movement including walking, running, scampering, and rolling
Pen exploration	Sniffing, touching, sucking or chewing any object that is part of the pen
Drinking	Drinking water or manipulating the drinker with or without ingestion of water
Feeding	Head positioned in the feeder or chewing food displaced from the feeder
Excretion	Defecating or urinating
Tail biting	Having the tail of another pig in its mouth and biting or pulling hard enough to cause a reaction in the other pig
Belly nosing	Repeated thrusting of snout into the belly of another pig
Fighting	Head-thrusting, ramming, biting, or pushing another pig
Other social	All other social interactions including mounting, head rubbing, and nosing parts of the body other than the belly
Other	All other behaviors not listed above