A viable less-invasive alternative for continuous temperature measurement in weaned pigs

Authors: Sanchez, Nicole; Dailey, Jeffery; Broadway, Paul; DAVIS, EMILY - Texas Tech University; BOWEN, BROOKE - Texas Tech University; PETRY, AMY - Texas Tech University; BALLOU, MICHAEL - Texas Tech University; HALES, KRISTIN - Texas Tech University; Carroll, Jeffery - Jeff Carroll

Submitted to: Livestock Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2022
Publication Date: 1/1/2023
Citation: Sanchez, N.C., Dailey, J.W., Broadway, P.R., Davis, E.M., Bowen, B.M., Petry, A.L., Ballou, M.A., Hales, K.E., Carroll, J.A. 2023. A viable less-invasive alternative for continuous temperature measurement in weaned pigs. Livestock Science. 267. Article 105126. https://doi.org/10.1016/j.livsci.2022.105126.
DOI: https://doi.org/10.1016/j.livsci.2022.105126

Interpretive Summary: Increased body temperature is a key sign of illness in livestock. It can also be used to detect differences in stress responses and differences due to breed and sex. Finding a reliable method of measuring body temperature that provides accurate and timely data is very important to swine research. Current methods for measuring body temperature in pigs are either infrequent or invasive. Therefore, this study sought to find a less invasive alternative for measuring body temperature. Specifically, scientists compared abdominal cavity temperature with temperature measured under the skin in weaned pigs. A fever response was induced by treating pigs with a bacterial toxin. Results from this study suggest that temperature measured under the skin in between the abdomen and the hind leg can be an alternative to more invasive methods. This method can provide an important tool to researchers and health professionals. These data will be of interest to researchers in the field of swine physiology and immunology, and health professionals interested in measuring frequent body temperature.

Technical Abstract: The objective of this study was to compare intraperitoneal (IP) body temperature with temperature measured subcutaneously in weaned pigs. In experiment 1, weaned pigs (n = 10; 5.9 ± 0.3 kg BW) were fitted with temperature loggers in four different anatomical locations. The first three temperature loggers were place subcutaneously: 1) behind the right ear (Ear). 2) in the skin fold between the abdomen and left front leg (Shoulder), and 3) in the skin fold between the abdomen and the right hind leg (Flank). The fourth temperature logger was placed surgically within the intraperitoneal cavity (IP). The next day, pigs were administered lipopolysaccharide (LPS, 15 µg/kg BW, intraperitoneal). Loggers were retrieved following euthanasia 24-h post-challenge. In experiment 2, weaned pigs (n = 36; 4.7 ± 0.2 kg initial BW) were fitted with temperature loggers subcutaneously in the Flank and surgically within the IP cavity. After 5 d, pigs were challenged intravenously with LPS (15 µg/kg BW). Forty-eight hours post-LPS challenge pigs were humanely euthanized and temperature loggers were retrieved. Temperature was measured every 5 min from -12 to 24 h relative to LPS administration in both experiments. In experiment 1, a temperature logger location × time interaction (P < 0.01) was observed such that temperature measured IP and subcutaneously at the Flank was greater than temperature measured at the Ear and Shoulder throughout the study. Correlation analysis found the strongest correlations between IP and Flank subcutaneous temperature (r = 0.75 to 0.88; P < 0.01). In experiment 2, temperature measured IP was greater (P < 0.01) than temperature measured subcutaneously at the Flank (39.36 vs. 39.10 ± 0.04C). Therefore, data from this study suggest that temperature loggers placed subcutaneously at the Flank can be used as a less-invasive alternative to intraperitoneal temperature measurement in weaned pigs.