Table 33.

Assessment of ABM for resting problems (lying behaviour) in terms of feasibility, sensitivity and specificity

ABM	Description of the ABM
Lying time	Definition: Time spent with flank in contact with ground (Winckler et al., 2015). Short lying time (< 10 h) for cows housed indoors indicative of resting problems. The 10‐h criterion does not apply to cows on pasture, cows in oestrus and cows in the peri‐partum period. Feasibility: Low ‐ Validated activity monitors are not widely available on farm yet. Since 24 h observations are required, direct observations are time‐consuming. Sensitivity and Specificity: High sensitivity and low specificity (lying time can be prolonged in situations of lameness or illness and will be shorter in heat stressed cows)
Frequency of lying bouts	Definition: Number of times a cow is lying per day (Ledgerwood et al., 2010). A higher number of lying bouts indicates discomfort and/or disturbances while lying. Feasibility: Low ‐ see Lying time. Sensitivity and Specificity: Low sensitivity and low specificity (difficult to interpret, lower frequency of lying bouts (and therefore often longer lying bouts) may reflect problems in changing posture but resting uncomfortably may lead to higher frequency of lying bouts).
Duration of lying down movement	Definition: Duration of behaviour sequence starting with bending of the first carpal joint and ending with pulling out the front leg after the hindquarter has touched ground (Welfare Quality®, 2009). Longer duration indicative of a higher degree of restriction. Feasibility: High ‐ Direct observation of spontaneous lying down movements at individual level; may be time‐consuming depending on herd size. Sensitivity and Specificity: Low sensitivity (intention to lie and interruptions to lying down movement have a higher specificity than the lying down movement itself) and low specificity (animals with leg problems will take longer to lie down).
Deviation from normal, uninterrupted getting up movement	Definition: Degree of deviation ranging from smooth fluid movement/normal sequence of events, over short pause on knees/normal sequence, long pause on knees/normal sequence, long pause on knees and/or some difficulty in rising, e.g. awkward twisting of head and neck/normal sequence to abnormal rising/deviation from the normal sequence of events (Chaplin and Munksgaard, 2001). Observation of getting up movement easily captures the ability of the cow to get up. Degree of welfare impairment increases with score for getting up movement. Feasibility: High ‐ Via direct observation at individual level; rising movements can be assessed in a standardised test situation, i.e. encouraging the cows to stand up. Sensitivity and Specificity: High sensitivity and high specificity (knee injuries and lameness can cause false positives, but such welfare issues may be accounted for from concurrent assessments).
Lying behaviour synchronisation	Definition: Percentage of animals simultaneously exhibiting the same posture (here: lying). Different thresholds of synchronous posture are possible (e.g. 70, 80, or 100%; Stoye et al., 2012). Degree of synchrony positively associated with welfare as it indicates that there are sufficient resources available for all individuals. Feasibility: Low ‐ see Lying time Sensitivity and Specificity: High sensitivity (more sensitive than lying times for resting problems) and low specificity (competition/group stress may lead to low synchrony).