State of the art and the future of fecal analysis using infrared spectroscopy

Assessing the health and wellbeing of animals in their natural habitats is a critical yet difficult aspect of species management and conservation. Non- and minimally invasive techniques are increasingly being sought by people working with animals so they can easily monitor the health and wellbeing of the animals without causing them distress. One noninvasive technique that has been in this space is infrared (IR) spectroscopy, which measures the interaction of IR radiation with matter. The ability of IR spectroscopy, especially near-infrared (NIR) and mid infrared (MIR) spectroscopy, to evaluate and monitor animal nutrition, as well as to discriminate physiological attributes of animals (e.g., stress, reproductive status), has been demonstrated by several studies with livestock and wildlife species. However, the use of IR spectroscopy techniques is laden with several challenges, including sample preparation and stability, reliability, and transferability of prediction models. This paper reviews research on the analysis of fecal samples using IR spectroscopy as a proxy in animal health and wellbeing studies. The main challenges of using IR spectroscopy as a portable technology for in-field analysis are also discussed while highlighting key aspects to be considered for in-field applications of NIR and MIR spectroscopy in animal health and wellbeing studies.