Longitudinal and transverse carbon isotope profiles were performed on tooth dentine from five steers (Bos taurus) initially fed C₃ and subsequently C₄-dominant food. Comparison of different protocols for bioapatite extraction revealed that the use of NaOCl considerably reduced the amplitude of variation of δ¹³C within a tooth. Increasing contribution of C₄ food to the carbon isotope composition of bioapatite was found from the tip of the tooth crown to the neck and from the enamel–dentine junction toward the pulp cavity. These findings confirm that the model of dentine growth as a succession of stacked cones applies to bovines. Temporal resolution is estimated to be 4months in transverse profiles, significantly better than in longitudinal dentine profiles (8–9months) or even in profiles derived from enamel of the same individual (6–7months). Temporal resolution could be improved by a factor of two by selecting a different sampling zone or refining our sampling protocol. This sampling strategy could also be applied to dentine collagen and has important ecological and archaeological implications including determination of the season of weaning, or the reconstruction of mobility strategies.