Infrared thermography (IRT) is a non-invasive imaging method used to measure body surface temperature and detect variations in body temperature during physiological and pathological conditions, making IRT a potential tool for estrus detection. This study evaluated the accuracy of IRT in detecting estrus in smallholder beef cattle raised in smallholder farming systems. The measured parameters included environmental parameters (ambient temperature and relative humidity), physiological responses (rectal temperature, pulse rate, and respiration rate), and body surface temperatures in four regions (eye, muzzle, ear, and vulva). Data were collected from eight estrous and eight non-estrus cows of two breeds (Limousin-cross and Simmental-cross). The physiological responses did not differ significantly (p > 0.05) between the two breeds. Additionally, although the estrus Limousin-cross cows had higher body surface temperatures at all body regions, no differences were statistically significant (p > 0.05). The body surface temperatures of the eye, muzzle, ear, and vulva regions of Simmental-cross cows in estrus were higher (p<0.05) than those of non-estrus cows. Weak associations with ambient temperature indicate that the eye and vulva are reliable regions for IRT readings. In summary, IRT is a non-invasive, reliable, and accurate method for detecting estrus in cows.
Ma’rufi et al. (2026) studied this question.