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 ch anges occurring during their growth. The aim of our study is to understand how a dietary change is recorded in dentine collagen. Analyses were conduct ed on five steers (Bos taurus) raised in an experimental farm. From birth u ntil weaning the steers were fed on a C-3 diet; after weaning they were fat tened 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 is otopic 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 weanin g process is reflected by a decrease in (sic)N-15 that exactly coincides wi th 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. Archaeolog ical applications of this study are considered, including determination of the duration of lactation in prehistoric herds, and detection of residentia l mobility in cattle herders. Copyright 2001 Academic Press