Integration of animal husbandry and millet agriculture in Bronze Age East-central Eurasia revealed by faunal stable isotopes at the Jirentai Goukou site, Xinjiang

How food globalization in the Bronze Age influenced the economies and societies of regions along the Eurasian continent has attracted widespread attention. As an integral part of this food globalization, previous studies have focused on the impact of the westwards spread of millet crops on the human populations of East-Central Eurasia. However, the relationship between millet crops and key subsistence economies, such as animal husbandry, which humans rely on in East-Central Eurasia, remains unclear. Here, we carry out a new stable isotope study of 68 domesticated faunal bones from Bronze Age Jirentai Goukou site, Xinjiang, and combine about 1500 published stable isotope data of human and faunal bones to explore systemically the relationship between animal husbandry and millet agriculture in Bronze Age East-Central Eurasia. Our study reveals first the integration of animal husbandry and millet agriculture in Bronze Age Xinjiang, which is indicated by the adoption of C₄ millet byproducts to feed domesticated sheep/goats and cattle. Further wide-range stable isotopic analysis in Bronze Age East-Central Eurasia highlights the existence of two different patterns in the relationship between animal husbandry and millet agriculture: the Central Plains pattern and the Inner Asia pattern. These differences can be expressed clearly in several aspects, including the species of domesticated herbivores fed, the degree, method and seasonality of feeding sheep/goats and cattle, and the composition of fodder. On this basis, the possible reasons for the different patterns in the relationship between millet agriculture and animal husbandry in East-Central Eurasia are further explored, such as the different histories of agricultural and pastoral development between the Central Plains and Inner Asia, the distinct characteristics of agriculture and pastoralism (sedentary and mobile), and the specific social, economic/political and geographical environments. Our study provides important information for understanding the specific impact of the globalization of millet agriculture on the animal husbandry economy in Bronze Age Eurasia.