Table 12.

ABMs selected for the assessment of resting problems in pigs during preparation, in transit and journey breaks

ABM	Definition and interpretation of the ABM
Time spent standing	Definition: Time that pigs maintaining an upright position during transport. Interpretation: Pigs tend to spend more time standing during a transport stage in comparison with housing conditions because of the impossibility of lying down due to lack of space and/or excessive vibration‐motion of the truck.
Falling	Definition: Loss of balance, in which part(s) of the body (beside legs) are in touch with the floor (Dalmau et al., 2009; Welfare Quality®, 2009). Interpretation: Falling during transport occurs when there is a slippery floor surface, the driving style is not adequate, or animals are fatigued.
Sitting	Definition: Pigs have their hind quarters in contact with the trailer floor, and are propped up with weight on the fore legs. Interpretation: When space is limited, more sitting behaviour may be observed, as there is insufficient space for all pigs to lie. Sitting is a postural adjustment and space saving behaviour that has been associated with reduced space provision during transport (Urrea et al., 2021).
Lying behaviour after unloading	Definition: Pigs adopting a lying position, removing weight from their legs. Pigs may adopt a lying posture on their sternum, their lateral side, or be semi‐recumbent. Interpretation: An increased number of pigs lying down and additionally, adopting a lying posture rapidly after unloading is associated with greater fatigue during the journey (Urrea et al., 2021). There may also be a reduction in other behaviours (drinking, fighting), with pigs prioritising lying down (Dalla Costa et al., 2016; Urrea et al., 2021).
Blood creatine kinase	Definition: Creatine kinase (CK) measured in blood (serum or plasma) is an enzyme that is increased with muscle activity and injury (Hody et al., 2011). Interpretation: CK has been used as a measure to indicate stress and fatigue in pigs during transport. Pigs transported with lower space allowances show raised levels of CK, suggesting increased fatigue associated with a reduction in resting and increased posture adjustments/requirements to stabilise themselves as opposed to rest (Gerritzen et al., 2013; Urrea et al., 2021).

ABM: animal‐based measure.