The use of body surface temperatures in assessing thermal status of hutch-reared dairy calves in shaded and unshaded conditions

The study was carried out in a Hungarian large-scale dairy farm during 5-day period hot August weather. Altogether 16 preweaning calves were chosen for the study. An agricultural mesh with 80% shielding stretched over eight calf cages at 2 m from ground to shield their entirety, while others left unshaded. Ambient temperature and relative humidity measured 10 min intervals inside outside one of hutches shaded unshaded groups total length rectal by digital thermometer every 4 h. Surface temperatures on body parts, same as an infrared thermometer. Measuring sites included: leg (metacarpus), muzzle, eye bulb, scapula, ear. Statistical analyses performed assess effects shading environmental also strength association between core, skin ambient temperatures; estimate gradient shell core; compare changes heat dissipation capacity different regions (as represented various sites) increasing controlling or conditions; predict risk hyperthermia (rectal not lower than 39.5°C) CART classification method. average suggest that conditions both imposed severe load calves. shell, temperatures, shows much more significant variation, similar temperature. As expected, areas are closer core (ear eye) show less difference narrower range (lower variance), distal (leg, scapula) have wider range. Body surface related predictive value predicting stress is low.