Detection of dietary changes bg intra-tooth carbon and nitrogen isotopic analysis:: An experimental study of dentine collagen of cattle (Bos taurus)

Hypsodont teeth potentially contain a record of dietary or environmental changes occurring during their growth. The aim of our study is to understand how a dietary change is recorded in dentine collagen. Analyses were conducted on five steers (Bos taurus) raised in an experimental farm. From birth until weaning the steers were fed on a C-3 diet; after weaning they were fattened on a C-4/C-3 mixed diet until slaughter. Dentine collagen was sampled on demineralized molars from top to bottom. The change from the C-3 to the C-4/C-3 diet and weaning are both reflected in intra-tooth variations in (sic)C-13 and (sic)N-15 values, respectively. The abrupt change in carbon isotopic composition of the diet is reflected by a progressive change of the dentine collagen (sic)C-13 values. The gradual change may reflect sampling strategy and/or gradual turnover of the metabolic nutrient pool. The weaning process is reflected by a decrease in (sic)N-15 that exactly coincides with increase in (sic)C-13. This demonstrates that when steers are weaned to a protein-poor diet, (sic)N-15 traces the cessation of suckling. Archaeological applications of this study are considered, including determination of the duration of lactation in prehistoric herds, and detection of residential mobility in cattle herders. Copyright 2001 Academic Press