Fecal metabolomics as a novel non-invasive method for short-term stress monitoring in beef cattle

Traditional measures of short-term stress response such as fecal glucocorticoid metabolites (FGM) are widely used in controlled settings to quantify the intensity of stimulation to which cattle are exposed. However, FGM present several methodological and interpretation pitfalls when applied on animals in free-ranging conditions. In this study we proposed an NMR-based fecal metabolomics strategy for non-invasive stress detection in beef cattle. Using a longitudinal sample collection, we monitored the changes in the fecal metabolome and FGM concentrations before and after an acute stressful event. Our results showed that while the fecal metabolome changed as function of stress (p < 0.001), the mean concentrations of FGM did not change (Levene's test: F-ratio: 0.87, p-value: 0.44). Furthermore, we showed that the inter-animal variability observed in the stress response was correlated with the individual fecal microbiota. This result was in line with recent findings indicating the gut microbiome as a crucial ...