Table 3.

Ethogram used for the behavioural observations post-test interaction during 30 min in the home pen. Behaviours were coded as state events unless stated otherwise. Interruption of more than 2 s was considered a new bout. Definitions adapted from other studies are cited.

Category	Behaviour	Definition
Activity	Eat or drink	Focal pig has her head in the trough or in the drinker
	Eliminatesa	Focal pig excretes faeces or urine
	Explores	Focal pig’s snout touches pen fitting
	Immobile	Focal pig is either sitting or standing for more than 2 s and less than 30 s, and shows no specific movement
	Inactive (Sara Hintze, unpublished)	Focal pig is either standing, sitting or lying, show no specific movement for more than 30 s. Focal pig remains inactive if it engages in exploration maximum twice or for less than 5 s, takes less than five steps away, stretches or changes posture
	Lying down	Focal pig’s thorax touches the ground
	Locomotor play	Focal pig produces erratic movements with no clear purpose, sudden reversal of behaviours. Includes run, spring, pivot. Performed alone
	Object play	Focal pig nudges, chews, pulls or shakes enrichment (ball or rope)
	Social play67	Focal pig is performing playful behaviour with, or towards, another pig. Includes scampering, running, pivoting, head tossing, flopping or hopping
	Agonistic behaviour	Focal pig forcefully fights with another pig. Includes bites, head knocks and chasing. Usually not performed within a play bout
	Nose to nose	Focal pig is actively touching another pig’s snout with its snout (initiating the interaction)
	Nose to body67	Focal pig is actively touching another pig’s body part with its snout (initiating the interaction)
	Receives	Focal pig receives interaction from another pig: agonistic, nose-to-nose or playful
	Not visible	Focal pig is not clearly visible (i.e. typically snout is hidden) or its behaviour cannot be determined

^aScored as point event due to short duration.