Evaluation of an infrared thermography camera for measuring body temperature in dairy calves
The objective of this diagnostic accuracy study was to validate an infrared thermography (IRT) camera and its software (FLIR One, FLIR, Global) for accuracy and precision for ocular temperature readings to serve as a proxy for rectal temperature in commercially housed calves. A total of 318 male Hol...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2022-09-01
|
| Series: | JDS Communications |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2666910222000771 |
| _version_ | 1797788421945556992 |
|---|---|
| author | M.C. Cantor H.M. Goetz K. Beattie D.L. Renaud |
| author_facet | M.C. Cantor H.M. Goetz K. Beattie D.L. Renaud |
| author_sort | M.C. Cantor |
| collection | DOAJ |
| description | The objective of this diagnostic accuracy study was to validate an infrared thermography (IRT) camera and its software (FLIR One, FLIR, Global) for accuracy and precision for ocular temperature readings to serve as a proxy for rectal temperature in commercially housed calves. A total of 318 male Holstein calves were enrolled into this study from the day of arrival to a calf rearing facility until 14 d later. Researchers took an ocular temperature reading using an IRT camera, and a rectal temperature on each calf each day in the morning. The reference standard method for body temperature in the calves was rectal temperature. We assessed the data for agreement between the IRT and the reference standard using Pearson correlations by calf (accuracy), coefficients of determination (precision), and Bland-Altman plots for bias. In addition, a logistic regression model was built using the reference method as the outcome, with IRT as an explanatory variable to assess the diagnostic accuracy of IRT as an indicator of fever (rectal temperature ≥39.5°C). There was a negligible correlation between the IRT readings and rectal temperature (r = 0.22) and the coefficient of determination for IRT to predict rectal temperature was negligible (R2 = 0.05), suggesting poor precision. The average mean difference between the IRT data and rectal temperature was 0.55°C, and the differences between IRT and rectal formed a linear line around the mean difference, suggesting the Bland-Altman analyses showed proportional error and bias. The optimal probability cut-off for IRT readings for fever was at 39.5°C, and had a receiver operating characteristic area under the curve of 0.67, a sensitivity of 61%, a specificity of 71%, and 78% (3,134/4,427) of the samples were correctly labeled as either having a fever or not using IRT readings. In summary, the IRT camera and software were not validated for serving as a proxy for rectal temperature in commercially housed calves due to poor precision, and proportional error partially explained by ambient environmental conditions. We suggest that this infrared thermography system should not replace rectal temperature readings for use in commercially housed calves. |
| first_indexed | 2024-03-13T01:36:20Z |
| format | Article |
| id | doaj.art-e23f80a15a8c4e1b8d65b3a4c3dc1827 |
| institution | Directory Open Access Journal |
| issn | 2666-9102 |
| language | English |
| last_indexed | 2024-03-13T01:36:20Z |
| publishDate | 2022-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | JDS Communications |
| spelling | doaj.art-e23f80a15a8c4e1b8d65b3a4c3dc18272023-07-04T05:11:00ZengElsevierJDS Communications2666-91022022-09-0135357361Evaluation of an infrared thermography camera for measuring body temperature in dairy calvesM.C. Cantor0H.M. Goetz1K. Beattie2D.L. Renaud3Department of Population Medicine, University of Guelph, Guelph, ON, Canada, N1G 2W1Department of Population Medicine, University of Guelph, Guelph, ON, Canada, N1G 2W1Department of Population Medicine, University of Guelph, Guelph, ON, Canada, N1G 2W1Corresponding author; Department of Population Medicine, University of Guelph, Guelph, ON, Canada, N1G 2W1The objective of this diagnostic accuracy study was to validate an infrared thermography (IRT) camera and its software (FLIR One, FLIR, Global) for accuracy and precision for ocular temperature readings to serve as a proxy for rectal temperature in commercially housed calves. A total of 318 male Holstein calves were enrolled into this study from the day of arrival to a calf rearing facility until 14 d later. Researchers took an ocular temperature reading using an IRT camera, and a rectal temperature on each calf each day in the morning. The reference standard method for body temperature in the calves was rectal temperature. We assessed the data for agreement between the IRT and the reference standard using Pearson correlations by calf (accuracy), coefficients of determination (precision), and Bland-Altman plots for bias. In addition, a logistic regression model was built using the reference method as the outcome, with IRT as an explanatory variable to assess the diagnostic accuracy of IRT as an indicator of fever (rectal temperature ≥39.5°C). There was a negligible correlation between the IRT readings and rectal temperature (r = 0.22) and the coefficient of determination for IRT to predict rectal temperature was negligible (R2 = 0.05), suggesting poor precision. The average mean difference between the IRT data and rectal temperature was 0.55°C, and the differences between IRT and rectal formed a linear line around the mean difference, suggesting the Bland-Altman analyses showed proportional error and bias. The optimal probability cut-off for IRT readings for fever was at 39.5°C, and had a receiver operating characteristic area under the curve of 0.67, a sensitivity of 61%, a specificity of 71%, and 78% (3,134/4,427) of the samples were correctly labeled as either having a fever or not using IRT readings. In summary, the IRT camera and software were not validated for serving as a proxy for rectal temperature in commercially housed calves due to poor precision, and proportional error partially explained by ambient environmental conditions. We suggest that this infrared thermography system should not replace rectal temperature readings for use in commercially housed calves.http://www.sciencedirect.com/science/article/pii/S2666910222000771 |
| spellingShingle | M.C. Cantor H.M. Goetz K. Beattie D.L. Renaud Evaluation of an infrared thermography camera for measuring body temperature in dairy calves JDS Communications |
| title | Evaluation of an infrared thermography camera for measuring body temperature in dairy calves |
| title_full | Evaluation of an infrared thermography camera for measuring body temperature in dairy calves |
| title_fullStr | Evaluation of an infrared thermography camera for measuring body temperature in dairy calves |
| title_full_unstemmed | Evaluation of an infrared thermography camera for measuring body temperature in dairy calves |
| title_short | Evaluation of an infrared thermography camera for measuring body temperature in dairy calves |
| title_sort | evaluation of an infrared thermography camera for measuring body temperature in dairy calves |
| url | http://www.sciencedirect.com/science/article/pii/S2666910222000771 |
| work_keys_str_mv | AT mccantor evaluationofaninfraredthermographycameraformeasuringbodytemperatureindairycalves AT hmgoetz evaluationofaninfraredthermographycameraformeasuringbodytemperatureindairycalves AT kbeattie evaluationofaninfraredthermographycameraformeasuringbodytemperatureindairycalves AT dlrenaud evaluationofaninfraredthermographycameraformeasuringbodytemperatureindairycalves |