Table 1.

List of parameters measured in the study, level of sampling, references and description. The parameters were ordered according to the time-line of the study.

Type	Parameter	Level	Reference	Description
QBA 1	Qualitative Behaviour Assessment	Treatment group 4	[27]	The value was expressed in mm on a scale of 125 mm (Visual Analogue Scale for QBA).
BM 2	Social behaviour (negative and positive)	Litter	[27]	Modified from the reference. Negative social behaviour included any aggressive social behaviour or biting causing a response from the animal disturbed. Positive social behaviour consisted of sniffing, licking, playing and moving gently away from the other animal without an aggressive or fighting reaction from this individual. Negative and positive social behaviour were recorded, and they were expressed as the % of social behaviour (positive or negative)/ the % of total active behaviour (sum of social, exploratory and other behaviours).
BM	Exploratory behaviour (pen and environmental enrichment - directed)	Litter	[27]	Modified from the reference. Pen- and enrichment- directed exploratory behaviour were recorded, and they were expressed as the % of exploratory behaviour (pen or environmental enrichment directed)/ the % of total active behaviour (sum of social, exploratory and other behaviours).
BM	Other active behaviours	Litter	[27]	Any active behaviour not included in the previous categories.
BM	Inactive behaviour	Litter	[27]	Any behaviour when the animal remained motionless thus without any activity.
BM	Tail biting (TB)	Litter	-	The piglets were attempting to manipulate or bite the tail of a pen mate.
BM	Ear biting (EB)	Litter	-	The piglets were attempting to manipulate or bite the ear of a pen mate.
BM	Body biting (BB)	Litter	-	The piglets were attempting to manipulate or bite a part of the body of a pen mate (e.g., flank, genitals, legs etc.).
BM	Fighting (F)	Litter	-	Piglets involved in the fighting.
BM	Play (P)	Litter	-	Piglets playing with one or more pen mates.
BM	Tail position	Individual	[30]	Tail posture was classified as follows: curly tail; tail hanging down; tail tucked down (down and tucked to the body).
LHM 3	Skin lesions	Individual	[27]	Considers 5 separate areas (ear, front, middle, hind-quarters, legs). Score was 0 = up to 4 visible lesions; 1 = 5–10 visible lesions; 2 = 11 to 15 visible lesions.
LHM	Tail lesions	Individual	[27]	Modified from the reference. 0 = absence of lesions; 1 = superficial biting along the length of the tail but no evidence of swelling or blood; 2 = fresh blood visible on the tail, the presence of a scar, swelling, or missing a part of the tail.
LHM	Tear staining	Individual	[31]	The presence of red tears in the left eye. Modified from the reference as follows: 0 = absence of staining; 1 = staining barely detectable or less than 50% of the total eye area; 2 = staining up to 100% of the eye area or extending below the mouth.
LHM	Low body condition score	Individual	[27]	Any piglets which were very lean or too small when compared to the others in the litter.
LHM	Diarrhoea	Individual	[27]	Modified from the reference. The presence or absence of this parameter was assessed in each piglet observed individuals.
LHM	Neurological disorder	Individual	[27]	Modified from the reference. Includes muscle tremor or paddle-like limbs. In this category turned head, loss of equilibrium or any other clinical sign of a neurological disorder were also included. Presence or absence of this parameter was assessed in each observed individuals.
LHM	Hernia	Individual	[27]	Modified from the reference. The presence or absence of this parameter was assessed in each piglet observed.
LHM	Limb lesions	Individual	[27]	Modified from the reference. The presence or absence of this parameter was assessed in each piglet observed.
LHM	Lameness	Individual	[27]	Modified from the reference. The presence or absence of this parameter was assessed in each piglet observed.
LHM	Further care	Individual	[29]	Identifies animals which have to be removed from the pen, needing additional care or being emergency culled. The presence or absence of this parameter was assessed in each piglet observed.

¹ QBA = qualitative behaviour assessment; ² BM = behavioural measurement; ³ LHM = lesion and health measurement. ⁴ Treatment group = these groups corresponded to the 8 categories of the experiment.