Table 1 The definition of behaviors observed in individually and pair-housed (PAIR) calves pre- and post-disbudding.

Eating forage

Calf is taking hay or straw into the mouth followed by chewing and swallowing⁵⁰

Ruminating

Calf is chewing after regurgitating⁵⁰

Resting

Calf is lying in any resting position⁵⁰

Exploration

Calf is sniffing walls or bedding⁴¹

Play

Individual—object play, gallop, jump, leap, buck-kick, head-shake, turn, Social—play fight, mount⁵¹ (observed only in PAIR calves)

Head shaking

Calf rapidly shakes its head from one side to the other⁵²

Head rubbing

Calf lifts hind leg to scratch top of head with foot or rubs head against sides of the pen⁴³

Foot stamping

Calf raises one foot and brings it down again immediately⁴³

Self-grooming

Calf is licking itself⁵²

Social resting

Calf is lying close to other calf⁵³, i.e., they touch each other (observed only in PAIR calves)

Active allo-grooming

Calf is performing social licking (observed only in PAIR calves)

Passive allo-grooming

Calf is receiving social licking (observed only in PAIR calves)