Maternal behavior in sheep is characterized by the rapid establishment of individual recognition of the lamb through the use of different sensory modalities. Olfactory recognition mediates acceptance at suckling whereas visual/auditory cues are involved in recognition from a distance. This study investigates (a) the timing of both types of recognition and (b) whether they can be influenced by maternal experience. Olfactory recognition was assessed at lambing, 30 min, 1, 2, or 4 hr postpartum by presenting successively an alien and the familiar lamb. Recognition at a distance was assessed at 6, 8, and 12 hr postpartum by using a two-choice test between the familiar and an alien lamb. A majority (33/51) of ewes showed selectivity at suckling as early as 30 min after parturition, and no differences due to maternal experience were observed. By contrast, in the two-choice recognition test, multiparous ewes showed a preference for their familiar lamb at 6 hr whereas primiparous mothers did so only after 24 hr of mother-young contact: The performance of biparous mothers was intermediate. Thus, both types of recognition can be rapidly established after parturition, and maternal experience has a differential effect on the dynamics of these learning processes.
Copyright 2003 Wiley Periodicals, Inc. Dev Psychobiol 43: 167-176, 2003.