Use of infrared thermography in assessing the thermal comfort of cattle–systematic review

Abstract

Heat stress is one of the main challenges of cattle farming in tropical and subtropical regions, affecting productivity, reproduction and welfare. With the increase in the frequency and intensity of heat waves, efficient monitoring becomes essential. Traditional physiological methods, such as rectal temperature and respiratory rate, although effective, are invasive and require restraint, limiting large-scale use. In this context, infrared thermography (IRT) emerges as a non-invasive and agile technique to measure surface temperature and identify changes related to thermoregulation. Therefore, the objective of this study was to describe the use of infrared thermography in assessing thermal comfort in cattle (Bos taurus, Bos indicus, and their crossbreeds). This literature review, conducted between 2020 and 2025 in the ScienceDirect and PubMed databases, was guided by PRISMA and composed of 83 articles, aimed to synthesize evidence on the applications, thermal windows, and limitations of IRT in cattle. The results indicate that orbital, nasal, vulvar and udder regions are more reliable for correlating surface temperature with classical environmental indices. IRT has been applied to lactating dairy cows, beef cattle under silvopastoral systems and integrated with artificial intelligence algorithms. Despite methodological and environmental limitations, IRT is consolidated as a promising tool for management, sustainability and welfare decisions in livestock.