## 1 Introduction  
The current possibilities of technology, automation and digitalization allow researchers to collect, store and evaluate data online, which can result in information about the welfare of animals in terms of the animal's health or well-being. These data allow us to immediately use devices that can control part of the technology or adjust the unsatisfactory microclimate parameter. Automation of the measurement of physiological and behavioral parameters of farm animals carried out with minimized disturbance can ensure the timely and correct diagnosis of the health status of cows, allow the prevention of the development of infection and more accurate detection of estrus, and leads to a reduction in environmental stress. Accurate data and accumulated knowledge about farm animals, especially in cattle breeding, save working time and contribute to more efficient herd management [1, 2, 3, 4]. Among the physiological parameters, body temperature and its fluctuations are key indicators of animal health and well-being. Body temperature is used to assess the regularity of estrus and ovulation [5, 6], pregnancy [7], increased stress reaction [6], parturition [8] and incidence of disease in cows [4, 5, 9]. The manual measurement of body temperature is expensive and time-consuming. A potential risk of disease transmission is created, and it is also impractical for the cattle and technical staff to measure temperature throughout the daily cycle [7, 10, 11, 12, 13]. Some authors have investigatedthe possibility of the automatic measurement of bolus reticulo-ruminal temperature [5; 14], as well as the automatic detection of body temperature through the implantation of a temperature sensor in the vulvar muscles of cows [14; 15; 16; 17]. A non-invasive and safe method is infrared thermography, which displays temperature maps of the measured objects. Any object warmer than 0 Kelvin forms a heat emitter in the infrared part of the spectrum, which is not visible to the human eye. However, with the development of technology, measurement systems have been developed and they can visualize data that can be evaluated statistically [18]. They are used not only in industry, but also in agriculture in the field of veterinary medicine. [PERSON] et al. [19] reviewed the use of various non-invasive methods for measuring heat-stress levels in cattle and highlighted the importance of infrared thermographic imaging for the accurate and rapid determination of external body surface temperature. The measurement of dairy cow body temperature using infrared thermography (IRT) has shown that the eye, vulval temperature and the highest surface temperature (ST) are good points for determining animal core temperature [18; 20]. Due to the fact that IRT can be affected by air velocity and exposure to direct sunlight [21], it can be difficult to obtain an accurate body temperature using IRT image analysis in an unprofessional manner [18; 20]. In recent years, many measurements have been made using IRT as a tool to obtain thermal responses in a rapid and non-invasive manner [21]. Core body temperature can be used as an indicator of stress due to excessive heat or cold because its variation between animals is relatively small in a given environment. According to [PERSON] et al. [22], an increase in the value of RT by 1 \({}^{\circ}\)C causes a decrease in their productivity in different types of farm animals. IRT has been successfully used to determine the body-surface temperature of various animal species [17; 23; 24]. The use of IRT in animal production is cheap, fast, efficient and provides important information without the need for physical contact with the animals [25]. IRT allows the detection of even small temperature changes with accuracy [26], and therefore, it has become important in experiments as a safe method of assessment. IRT has been adopted in animal studies for various analyses, such as metabolic responses to heat stress [27] and diagnostics of inflammatory processes [28; 29].