. 2023 Mar 29;21(3):e07896. doi: 10.2903/j.efsa.2023.7896

Table 4.

ABMs for isolation stress in individual pens in dairy farms

ABM	Comments
Response in standard social approach test	Definition: Latency to approach an unfamiliar calf. Higher latency to approach an unfamiliar calf indicates a higher fear to other calves due to isolation (Jensen and Larsen, 2014) Sensitivity: High Specificity: High
Abnormal oral behaviours	Definition: Oral manipulation, including excessive licking, of non‐feed items such as pen fixtures or bedding (Jensen and Larsen, 2014) Sensitivity: Low, because not all calves experiencing isolation will show abnormal behaviours Specificity: Low, because this behaviour can be due to other causes (e.g. inability to suck)
Fear response	Definition: Startle response (e.g. withdrawal or freezing) when presented with a sudden external visual and/or auditory stimulus, e.g. the rapid opening of an umbrella (Boissy et al., 2001) Sensitivity: High Specificity: Low, because this ABM could also occur in situations of poor animal handling

ABM

Comments

Response in standard social approach test

Definition: Latency to approach an unfamiliar calf. Higher latency to approach an unfamiliar calf indicates a higher fear to other calves due to isolation (Jensen and Larsen, 2014)

Sensitivity: High

Specificity: High

Abnormal oral behaviours

Definition: Oral manipulation, including excessive licking, of non‐feed items such as pen fixtures or bedding (Jensen and Larsen, 2014)

Sensitivity: Low, because not all calves experiencing isolation will show abnormal behaviours

Specificity: Low, because this behaviour can be due to other causes (e.g. inability to suck)

Fear response

Definition: Startle response (e.g. withdrawal or freezing) when presented with a sudden external visual and/or auditory stimulus, e.g. the rapid opening of an umbrella (Boissy et al., 2001)

Sensitivity: High

Specificity: Low, because this ABM could also occur in situations of poor animal handling