Optimising non-invasive cortisol measurement in sheep (Ovis aries)

Faecal glucocorticoid metabolite analysis provides a robust non-invasive tool for assessing baseline and acute stress responses of livestock in relation to environmental stressors. In this research project, we quantified faecal cortisol metabolites (FCMs) in sheep using a broad-spectrum polyclonal antibody enzyme-immunoassay. We quantified the underlying variation in FCMs levels in sheep grazing a 'toxic pasture' (Biserrula pelecinus) known to cause primary photosensitization (PS)-skin inflammation. Sheep ingesting B. pelecinus had significantly higher FCM levels than controls suggesting a physiological stress response. In conclusion, non-invasive FCM EIA can be applied to assess physiological stress in sheep on farms to assist in addressing health and welfare concerns.