Infrared thermography is a possible technique for estimation of parturition onset in sows

Background: This study explores the possibility of using infrared thermography to estimate impending parturition in sows. Infrared devices were used to obtain the superficial body temperature from auricular skin of the sows along with rectal temperature. Three commercial piglet producing farms were included in this study. At two of the farms (1 and 2), the sows were loose housed. At the third farm (Farm 3), the sows were housed in farrowing crates. Temperature measurements from both primiparous and pluriparous sows were taken from approximately one week before the anticipated farrowing date until 24 hours postpartum. Body condition score and parity was documented from each sow. The sows’ activity levels, respiratory rates and environmental temperatures were logged along with skin temperature measurements.Results Auricular skin thermography from two different infrared devices revealed an increase in temperature starting between 16 and 8 hours before farrowing. From 16 hours ante partum to farrowing, the mean auricular skin temperature rose by 3.3 °C and 2.9°C measured with infrared camera and infrared laser thermometer, respectively. Following farrowing, the sows’ skin temperature dropped abruptly. Rectal temperature increased by only 0.4°C in the same time interval. Adjusting for differences between farms, sow activity and respiration rate, we found an average increase of the sows’ skin temperature by 2 °C or more within the last 16 hours before farrowing.ConclusionsMonitoring auricular skin temperatures of sows using infrared thermography individually one week before expected farrowing could provide a baseline temperature for each sow from which a sudden rise in temperature of approximately 2°C or more will be indicative of parturition in the following 8 h. This may lead to more efficient allocation of human assistance during farrowing time and thereby improve farrowing management and welfare of sows and their offspring.