Seasonal calving in European Prehistoric cattle and its impacts on milk availability and cheese-making.

Present-day domestic cattle are reproductively active throughout the year, which is a major asset for dairy production. Large wild ungulates, in contrast, are seasonal breeders, as were the last historic representatives of the aurochs, the wild ancestors of cattle. Aseasonal reproduction in cattle is a consequence of domestication and herding, but exactly when this capacity developed in domestic cattle is still unknown and the extent to which early farming communities controlled the seasonality of reproduction is debated. Seasonal or aseasonal calving would have shaped the socio-economic practices of ancient farming societies differently, structuring the agropastoral calendar and determining milk availability where dairying is attested. In this study, we reconstruct the calving pattern through the analysis of stable oxygen isotope ratios of cattle tooth enamel from 18 sites across Europe, dating from the 6th mill. cal BC (Early Neolithic) in the Balkans to the 4th mill. cal BC (Middle Neolithic) in Western Europe. Seasonal calving prevailed in Europe between the 6th and 4th millennia cal BC. These results suggest that cattle agropastoral systems in Neolithic Europe were strongly constrained by environmental factors, in particular forage resources. The ensuing fluctuations in milk availability would account for cheese-making, transforming a seasonal milk supply into a storable product.

The evolution of dual meat and milk cattle husbandry in Linearbandkeramik societies.

Cattle dominate archaeozoological assemblages from the north-central Europe between the sixth and fifth millennium BC and are frequently considered as exclusively used for their meat. Dairy products may have played a greater role than previously believed. Selective pressure on the lactase persistence mutation has been modelled to have begun between 6000 and 4000 years ago in central Europe. The discovery of milk lipids in late sixth millennium ceramic sieves in Poland may reflect an isolated regional peculiarity for cheese making or may signify more generalized milk exploitation in north-central Europe during the Early Neolithic. To investigate these issues, we analysed the mortality profiles based on age-at-death analysis of cattle tooth eruption, wear and replacement from 19 archaeological sites of the Linearbandkeramik (LBK) culture (sixth to fifth millennium BC). The results indicate that cattle husbandry was similar across time and space in the LBK culture with a degree of specialization for meat exploitation in some areas. Statistical comparison with reference age-at-death profiles indicate that mixed husbandry (milk and meat) was practised, with mature animals being kept. The analysis provides a unique insight into LBK cattle husbandry and how it evolved in later cultures in central and western Europe. It also opens a new perspective on how and why the Neolithic way of life developed through continental Europe and how dairy products became a part of the human diet.

Spatial distribution of trace element Ca-normalized ratios in primary and permanent human tooth enamel.

The trace elements distribution embedded in tooth enamel offers a means to study exposure of toxic metals and allows the reconstruction of dietary behaviors. The quantification of most of the elements with a spatial high resolution (~50µm) is routinely achieved using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). However, the lack of a comprehensive framework of trace elements distribution in enamel jeopardizes any endorsed sampling strategy using LA-ICPMS. The present work is an effort to improve our knowledge on this issue. We studied a suite of 22 sectioned teeth with known dietary history, including 12 3rd molars from 12 living individuals and 10 primary teeth from 3 living individuals. Using LA-ICPMS, we measured Ca, Cu, Zn, Ni, Sr, Ba and Pb variations along 2 or 3 rasters from cervical to occlusal enamel. Calcium concentrations are lower in primary than in permanent teeth and do not vary spatially within a tooth suggesting that enamel matures homogeneously before eruption. The Pb/Ca ratio does not vary within tooth enamel and between primary and permanent tooth enamel. The Cu/Ca and Ni/Ca ratios do not vary within tooth enamel but discriminate primary from permanent tooth enamel. The Zn/Ca ratios are higher in permanent than in primary tooth enamel, and increase up to an order of magnitude in the last hundred of microns at the enamel surface. The Sr/Ca and Ba/Ca ratios are higher in permanent than in primary tooth enamel, and decrease from the enamel-dentine junction towards outer enamel in permanent but not in primary tooth enamel. Considering the Ca-normalized intra-tooth variations of Zn, Sr and Ba, we recommend to perform laser ablation rasters along the enamel-dentine junction because this area is likely to retain most of the original and complete chemical information related to individual's life.