Measuring core body temperature is used as part of the diagnostic process in assessing the health of animals. Typically in calves, this is carried out using a rectal thermometer which can be time consuming, stressful to the calf and is invasive by nature. A non-invasive technique that is gaining recognition is thermal imaging. This study investigated the use of thermal imaging as a technique to assess core body temperature in pre-weaned artificially reared calves. A total of 125 male and female calves had rectal temperatures measured daily from day 7 until day 40 of life, and at the same time had a thermal image taken of the area around the medial canthus of the eye. A weak correlation (r = 0.28) was found between calf rectal temperature and thermal image temperature. A multivariable predictive model for core body temperature increased the correlation (r = 0.32) when including the environmental parameters of air temperature (p < .001) and wind speed (p < .001) as well as reconstituted milk replacer consumption (p < .01). The effectiveness of a predictive model including these parameters for the detection of calves with a core body temperature ≥ 39.5 °C was examined and found to have a sensitivity of 0% and a specificity of 100%. The results of this study demonstrate the need to take thermal environmental parameters into consideration when using thermal imaging to assess body temperature. However, the results suggest that accurate measures of core body temperature using thermal imaging cannot be achieved under commercial farm conditions. Further research is needed to determine what other factors could be measured to increase predictive ability.

中文翻译：

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在农场条件下对断奶前犊牛发热症进行热成像和直肠温度诊断的比较。

测量核心体温被用作评估动物健康状况的诊断过程的一部分。通常在小牛中，这是使用直肠温度计进行的，该温度计很费时间，对小牛有压力，并且天生具有侵入性。热成像是一种获得认可的非侵入性技术。这项研究调查了热成像技术作为评估断奶前人工饲养犊牛核心体温的技术。从生命的第7天到40天，每天总共测量125只雄性和雌性小牛的直肠温度，同时对眼内侧can周围区域进行热图像拍摄。小腿直肠温度与热像温度之间存在弱相关性（r = 0.28）。当包括气温（p <.001）和风速（p <.001）以及重构奶替代品的消耗量（p <。）的环境参数时，核心体温的多变量预测模型提高了相关性（r = 0.32）。 01）。检验了包括这些参数的预测模型对于检测核心体温≥39.5°C的犊牛的有效性，发现其灵敏度为0％，特异性为100％。这项研究的结果表明，在使用热成像评估体温时需要考虑热环境参数。但是，结果表明在商业农场条件下无法使用热成像准确测量核心体温。