Non-contact devices have been used in the measurement of body temperature in livestock production as a tool for testing disease in different species. However, there are few studies about the variation and correlations in body temperature between rectal temperature (RT) and non-contact devices such as non-contact infrared thermometers (NCIT) and thermal imaging/infrared thermography (IRT). The objective of this work was to evaluate the accuracy of non-contact devices to measure the body temperature in sheep, considering six body regions and the possibility of implementing these systems in herd management. The experiment was carried out at the experimental farm of the Catholic University of Valencia, located in the municipality of Massanassa in July of 2021, with 72 dry manchega ewes, and we compared the rectal temperature with two types of non-contact infrared devices for the assessment of body temperature in healthy sheep. Except for the temperature taken by NCIT at the muzzle, the correlation between RT vs. NCIT or IRT showed a low significance or was difficult to use for practical flock management purposes. In addition, the variability between devices was high, which implies that measurements should be interpreted with caution in warm climates and open pens, such as most sheep farms in the Spanish Mediterranean area. The use of infrared cameras devices to assess body temperature may have a promising future, but in order to be widely applied as a routine management method on farms, the system needs to become cheaper, simpler in terms of measurements and quicker in terms of analyzing results.
In Manchega sheep, correlations between temperatures across various body regions, including the udder, under differing environmental conditions, stages of lactation, and states of mammary gland health have not been extensively explored. To address this, a group of 108 Manchega sheep was evaluated monthly over a period of six months. Ambient, rectal, lacrimal, perianal, and udder surface temperatures, alongside mammary gland health status indicators such as somatic cell count (SCC) and microbiological milk culture, were recorded. This study investigated the correlations between these temperature measurements and SCC levels. Mammary glands were classified based on their SCC (greater or lesser than 400,000 cells/mL) and the results of the microbiological cultures (more or less than five colonies in 20 µL of milk). This study found no correlation between body surface temperatures and rectal temperatures. SCC showed a low negative correlation with udder surface temperatures. Notably, mammary glands with SCC levels exceeding 400,000 cells/mL exhibited lower udder surface temperatures. This research underscores the Manchega breed’s ability to adapt to varying ambient temperatures and the necessity for further studies to better elucidate the relationship between inflammation and temperature changes in the udder during intramammary infections.