Randomized field trial on the effects of body weight and short transport on stress and immune variables in 2‐ to 4‐week‐old dairy calves

Abstract Background Whether underweight calves respond differently to transport stress, enhancing their disease risk, is currently unknown. Objective To determine the effects of low body weight and transport stress on immune variables. Animals Twenty‐one 2‐ to 4‐week‐old male Holstein calves, housed on a commercial farm. Methods Randomized clinical trial. Full factorial design with 4 treatment groups: low body weight (≤46 kg)/no transport (LOWCON); low body weight/transport (LOWTRANS); normal body weight (>46 kg)/no transport (NORMCON), and normal body weight/transport (NORMTRANS). Transport duration was 2 hours. Results Transport significantly increased serum cortisol concentration (77.8 μg/mL; 95% confidence interval [CI], 37.8‐131.6; P