How Successful Can Infrared Thermography of the Mammary Gland Be in Detecting Clinical Mastitis in Sows?

The objective of the study was to ascertain the potential of infrared thermal imaging (IRT) to detect the development of clinical mastitis at an early stage. The study was carried out on a one-site small pig farm with 80 breeding sows (crossbreed Landrace × Yorkshire) that had a history of high incidence of MMA. The udder-skin temperatures of the breeding sows were measured using a high-quality IRT camera (FLIR T650sc), in accordance with the IRT measurement protocol (including calibration and corrections), with a measurement uncertainty of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>±</mo><mn>0.5</mn></mrow></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo> </mo><mo>°</mo><mi mathvariant="normal">C</mi></mrow></semantics></math></inline-formula>. This study improves upon previous research by refining the measurement protocol and selecting more appropriate statistical methods to better analyze time-dependent data. To minimise the impact of measurement uncertainty, we propose the use of time-dependent trends (simple moving averages) caused by farrowing and lactation in place of the original IRT time series data. The findings indicate that a significant disparity between the maximum and minimum daily udder-skin temperature values, along with a pronounced maximal median of daily udder-skin IRT temperature values in sows during the early post-farrowing period, is associated with an elevated prevalence of multiglandular mastitis. Consequently, the utilisation of IRT imaging of the udder skin has the potential to facilitate the detection or prediction of multiglandular mastitis in sows. However, identifying uniglandular mastitis in individual mammary glands is more complex and may rely on time-dependent statistical trends derived from IRT imaging.