Table 20.

ABMs for heat stress in outdoor feedlots

ABM	Comments
Respiration rate (RR)	Description: Frequency of breathing, usually measured by counting the movements of the flank manually and converting it into breaths per minute. Sensitivity: High. Specificity: Low. Pneumonia can also cause high respiratory rate.
Panting score	Description: A panting score was described by with 5 grades (0 – normal respiration; 1 – elevated respiration; 2 – moderate panting and/or presence of drool or small amount of saliva; 3 – heavy open‐mouthed panting; saliva usually present; 4 – severe open‐mouthed panting accompanied by protruding tongue and excessive salivation; usually with neck extended forward (Mader et al., 2006). Sensitivity: High. Specificity: Low. Pneumonia or exercise can also cause panting.
Body temperature	Description: Body temperature will increase above 39.5°C in animals in heat stress. Rectal temperature is the conventional way to measure temperature in cattle, but technology has provided alternatives such as thermography or intra‐ruminal bolus (Stygar et al., 2021). Sensitivity: High. Specificity: Low. Body temperature may also increase in cases of infectious disease.
Sweating	Description: Loss of heat through evaporation (Idris et al., 2021). Visual signs of sweating in cattle are wet patches along animals' backs and shoulders. Sensitivity: Low. Cows sweat at a low rate so that it may be imperceptible (Gebremedhin et al., 2008; Wang et al., 2020). Specificity: High.