Domesticated animals formed an important element of farming practices in prehistoric Britain, a fact revealed through the quantity and variety of animal bone typically found at archaeological sites. However, it is not known whether the ruminant animals were raised purely for their tissues (e.g., meat) or alternatively were exploited principally for their milk. Absorbed organic residues from pottery from 14 British prehistoric sites were investigated for evidence of the processing of dairy products. Our ability to detect dairy fats rests on the observation that the ␦ 13 C values of the C18:0 fatty acids in ruminant dairy fats are Ϸ2.3‰ lower than in ruminant adipose fats. This difference can be ascribed to (i) the inability of the mammary gland to biosynthesize C 18:0; (ii) the biohydrogenation of dietary unsaturated fatty acids in the rumen; and (iii) differences (i.e., 8.1‰) in the ␦ 13 C values of the plant dietary fatty acids and carbohydrates. The lipids from a total of 958 archaeological pottery vessels were extracted, and the compound-specific ␦ 13 C values of preserved fatty acids (C16:0 and C18:0) were determined via gas chromatography-combustion-isotope ratio mass spectrometry. The results provide direct evidence for the exploitation of domesticated ruminant animals for dairy products at all Neolithic, Bronze Age, and Iron Age settlements in Britain. Most significantly, studies of pottery from a range of key early Neolithic sites confirmed that dairying was a widespread activity in this period and therefore probably well developed when farming was introduced into Britain in the fifth millennium B.C.
There is little doubt that domesticated cattle, sheep, goats, and pigs were an integral part of early Neolithic farming in Britain. However, difficulties in establishing whether they were exploited for dairy products, wool, and traction, the so-called ''secondary products'' (1), has proved to be a major hurdle in our understanding of the evolution of prehistoric economies. The recognition by early farmers that animals could be reared for their milk would have had major impacts on diet, health, and subsistence economy (2). As such, it is of great archaeological and scientific interest to determine how these domesticates were utilized in antiquity: were they valued primarily as a meat source, were they exploited for their ''secondary products'' such as milk, or were different economic strategies used to maximize the production of both commodities? Evidence for dairying in prehistory is currently limited to certain specialist vessels, e.g., putative cheese strainers (3), and evidence from faunal remains of herds that are suggestive of dairying (4, 5). However, direct chemical evidence for widespread dairying at prehistoric sites anywhere in the world is currently lacking.Degraded animal fats, recognized by the high abundances of n-hexadecanoic (C 16:0 ) and n-octadecanoic (C 18:0 ) acids, are preserved widely within archaeological pottery, particularly those vessels involved in the preparation, consumption, and...
