Livestock activity biomarkers: Estimating domestication and diet of livestock in ancient samples

Abstract Faecal matter is commonly recovered from archaeological sites related to human/animal activity. The identification of its source is essential to understand the domestication process and the relationship between humans and domestic animals in ancient times. Additionally, faecal matter is useful for determining the diet of animals. Therefore, the use of an appropriate biomarker is essential. The ratios of 5β-Stanols and bile acid biomarkers are most commonly used to identify the biogenic origin of faecal matter. However, other biomarkers such as archaeol can be a good proxy for ruminants. Conversely, plant-based diet of the animals can be discerned by analysis of faecal matter. n-Alkanes are the most common proxies of the animal diet, followed by long-chain fatty acids and long-chain alcohols, and the interest in the analysis of carbon isotopes has recently increased owing to the possibility of distinguishing animal diets. In this review, we describe the identification of faecal and diet biomarkers in animals. Ratios and proxies used in archaeological fields are also described and discussed to determine the best approach for accurate identification.