Different methods of assessing udder temperature through thermography and their relation with rectal temperature

Thermography for disease detection in livestock: A scoping review

“…Figure 4 shows the range of emissivity values used for each species in the review, ranging from 0.93 to 1.0. Of the 64 studies that stated emissivity, just 21 provided a source for the value used ( 10 , 11 , 14 , 15 , 20 , 22 , 30 , 33 , 36 , 37 , 42 , 43 , 47 , 50 , 51 , 54 , 55 , 58 , 66 , 68 , 69 ). Sources for these emissivity values were not immediately clear from the publication and this is explained below.…”

“…These 21 studies cited 24 references ( 14 , 32 , 50 , 54 , 61 , 66 , 117 – 134 ) with some studies citing more than one reference and some references being cited multiple times. Three studies ( 37 , 50 , 68 ) reference the IR camera user manual (offering the emissivity for living tissues of between 0.95 and 0.98) 2 , 3 , 4 , and three of the references were books ( 128 , 130 , 132 ). Some of these source studies were included in the 109 publications identified in this review ( 13 , 14 , 32 , 50 , 54 , 66 , 123 , 127 ).…”

“…Thermogram temperature was also shown to differ between seasons and reproductive phases. Stumpf et al documented a strong correlation between lateral udder and rectal temperatures in cattle ( r 2 = 0.897) ( 68 ), demonstrating that the udder area has great promise as an indicator of core body temperature. Respiratory rate in calves has also been investigated using IRT; the rate of flank movements as captured by optical imaging was compared with IRT of thermal fluctuations around nostrils ( 14 ) and, encouragingly, these readings were found to be highly correlated.…”

“…Some cameras have multiple lenses to allow for different applications. Reported fields-of-view ranged from 15° to 45° ( 11 , 27 , 63 , 68 , 83 , 93 , 114 ). Montanholi et al reported the use of all available lenses with one of the IR cameras they used in their research (a FLIR SC2000 with 12°, 24° and 45° lenses) and applied each lens at different distances and experimental settings ( 46 ).…”

Use of thermography to assess heat tolerance in cattle breeds

“…The rise in temperature of the areas photographed with infrared thermography corresponds to the increase in physiological parameters and for Knizkova et al (2007), the temperature variations on the body surface can be reliably monitored with thermography. Therefore, infrared thermography (IRT) use has grown in recent years (McManus et al, 2016b) and is a valuable tool for measuring heat tolerance in sheep and cattle under tropical conditions since it is non-invasive, safe and effective (Cardoso et al, 2015;Daltro et al, 2017;McManus et al, 2015;Stumpf et al, 2021). IRT can be used to measure eye temperature as an indicator of internal temperature and has proven to be a relatively easy technique, especially when compared to rectal thermometers, tympanic thermometers, and other thermometers with microchips and rumen boluses (Church et al, 2014).…”