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

Abstract

The objective of this study was to compare intraperitoneal (IP) body temperature with temperature measured in different subcutaneous locations in weaned pigs exposed to a lipopolysaccharide (LPS) challenge. 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 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 ± 0.04°C). 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.