text: Herbivores such as cows and sheep consume terrestrial plant matter (grass) which contains β-sitosterol as the principal sterol. β-sitosterol is the 24-ethyl derivative of cholesterol and can be used as a biomarker for terrestrial plant matter (see section). In the gut of these animals, bacteria biohydrogenate the double bond in the 5 position to create 24-ethyl coprostanol and so this compound can be used as a biomarker for faecal matter from herbivores. Typical values in different source materials can be seen in the table after Gilpin ().