Infrared thermography as an alternative technique for measuring body temperature in cattle

Authors: HOFFMAN, ASHLEY - Texas Tech University; LONG, NATE - Texas Tech University; SMOCK, TAYLOR - Texas Tech University; Carroll, Jeffery - Jeff Carroll; Sanchez, Nicole; Broadway, Paul; RICHESON, JOHN - West Texas A & M University; JACKSON, TREYLR - West Texas A & M University; HALES, KRISTEN - Texas Tech University

Submitted to: Proceeding of Plains Nutrition Council Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 3/31/2022
Publication Date: 4/13/2022
Citation: Hoffman, A.A., Long, N.S., Smock, T.M., Carroll, J.A., Sanchez, N.C., Broadway, P.R., Richeson, J.T., Jackson, T.C., Hales, K.E. 2022. Infrared thermography as an alternative technique for measuring body temperature in cattle. Proceedings of the Plains Nutrition Council Spring Conference. p. 178.

Interpretive Summary:

Technical Abstract: Rectal temperature (RT) is used as a proxy for body temperature, a key indicator of health, but measuring RT can yield inaccurate results by creating additional stress, and it is time consuming and invasive (Reuter et al., 2010). The use of infrared thermography (IRT) might be a viable, non-invasive alternative to RT in cattle. Therefore, our objective was to evaluate the use of IRT as an alternative to RT in 31 steers (652.1 ± 102.5 lbs) within a temperature-controlled environment prior to, during, and after an induced febrile response. Each steer was fitted with an indwelling rectal thermometer to monitor changes in RT every 5-min (averaged by hour), and Escherichia coli lipopolysaccharide (LPS) was administered intravenously to each steer to produce a febrile response. Infrared temperatures, measured at the lacrimal region of the eye, were collected in 60-min increments beginning at -1.5 to -0.5 and 6.5 to 12.5 h relative to LPS injection. Additionally, IRT temperatures were collected in 30-min increments beginning at 0.5 to 1.5, 2.5 to 3.5, and 4.5 to 5.5 h relative to LPS injection. The IRT temperatures were subsequently recorded at 18.5, 24.5, 36.5, and 47.5 h after injection. Steer was the experimental unit for all dependent variables. Correlation analyses were conducted using PROC CORR of SAS, where Pearson and Spearman correlation coefficients were evaluated between the RT and IRT. Data for RT and IRT also were analyzed using PROC MIXED with a model that included measurement method (RT or IRT), sampling hour, and method × sampling hour. Steer nested within temperature measurement method was included as a random effect and was the subject of the repeated measures analysis. Increases in RT and IRT were observed at 1 h, confirming that both methods could detect a febrile response. The two methods differed at -0.5, 0.5, 1.5, 5.5, 9.5, 10.5, 11.5, 18.5, 24.5, 36.5, and 47.5 h (P < 0.01), but otherwise did not differ (P = 0.1838). Infrared thermography measurements were greater than RT measurements at -0.5, 0.5, 1.5, and 5.5 h relative to LPS injection. Conversely, RT measurements were greater than IRT measurements at 9.5, 10.5, 11.5, 18.5, 24.5, 36.5, and 47.5 h relative to LPS injection. Across sampling times, a Pearson correlation of 0.71 (P < 0.01) was noted between the RT and IRT measurements with a Spearman correlation of 0.66 (P < 0.01) between measurements. These data indicate that IRT could be a viable alternative to RT, but further research under a variety of experimental conditions is needed to assess the utility of IRT more fully in practical settings.