Rapid analysis of fecal glucocorticoid metabolites: Testing an alternative method for measuring stress markers in chimpanzee

This study explores the application of two methods of spectroscopy; Near Infrared spectroscopy (NIR) and Fourier transform spectroscopy (FTIR) as alternative approaches for measuring glucocorticoid metabolites in chimpanzee feces. The goals of this study were twofold: The first was to determine if cortisol can be identified within the NIR and/or FTIR spectra of chimpanzee fecal hormone extract in ethanol solution. The second objective was to determine the capability of NIR and FTIR to predict FGM concentrations obtained using standard laboratory methods. Fecal glucocorticoid concentrations measured by Enzyme Immunoassay were used as the reference data of partial least square (PLS) regression of fecal extract NIR spectra and FTIR spectra. Low accuracies (NIR: R2 = 0.152; FTIR: R2 = 0.199) were obtained from regression models using data from both methods. Though this study did not successfully demonstrate the feasibility of using NIR and FTIR to qualify and quantify FGMs, it is likely not a reflection of the capabilities of the technology, but rather of appropriate sample types and preparation methods.