This paper examines the behaviour of heifers over 12 days following weaning/housing at 7 months of age. Weaning consisted of separation from the dam and transport by lorry from pasture to indoor pens. The animals used were 10 Salers and 10 Aubrac heifers reared by their own mothers, 10 Friesian heifers fostered by Salers mothers and 10 Friesian heifers artificially reared. Frequencies of “resting chin”, lying, standing, moving about and feeding were recorded over 24-h periods. Habituation to the new rearing conditions was reflected by an increase in the time spent “resting chin” or lying, a decrease in the time spent standing or moving, a reduction in the number of behaviour bouts and a strengthening of the circadian rhythm of activity. On the basis of these indexes, adaptation occurred by Day 2 in the artificially reared Friesians and by Day 4 in the other animals. Amongst these, the Salers habituated more slowly than the Friesians and more rapidly than the Aubrac heifers. Group differences were maintained up until the end of the experiment. Both the artificially reared and the suckled Friesians were less active than the Salers and the Aubracs and their activity profile was less fragmented. The Aubracs remained even more active than the Salers.