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À lire dans Physiology &#38; Behavior 147 (2015) 122–130 la publication d'un article soumis à cette revue dans le cadre du programme COLOSTRUM.Newborns prefer the odor of milk and nipples from females matched in lactation age: Comparison of two mouse strains.Syrina Al Aïn, Camille Goudet, Benoist Schaal ⁎, Bruno Patris ⁎Developmental Ethology and Cognitive Psychology Group, Center for Olfaction, Taste, and Food Science, Dijon, France,"ABSTRACT ""Newborn mice are attracted to mammary odor cues carried in murine milk and nipple secretions. However, murine milk odor is not equally attractive along lactation. The present study focuses on the differential response of 2 day-old mouse pups of C57Bl/6 (C) and Balb/C (B) strains to the odor of milk (Experiment 1) and nipples (Ex- periment 2) that are matched/unmatched in terms of pup's age or strain. In Experiment 1, C and B pups were test- ed in a series of tests simultaneously opposing either murine milk and a blank (water), or two milks collected in early and late lactation (lactation days 2 and 15, respectively) from females belonging to their own or the other strain. Results showed that C and B pups were attracted to the odor of the different milks regardless of the lacta- tion age and the strain of the donor female. Nevertheless, C and B pups preferred the odor conveyed by early- than late-lactation milk of either strain. Moreover, early-lactation milk from C females was more attractive than early-lactation milk from B females for pups of either strain. In Experiment 2, differential nipple grasping response of C and B pups was measured when they were exposed to nipples of females in early or late lactation. The proportion of C pups that grasped a nipple was greater when they were exposed to a nipple in early lactation regardless of the strain of the donor females, whereas the proportion of B pups that grasped a nipple was greater when they were exposed to a nipple in early lactation, but only from own strain. Thus, newborn mice prefer the odor of milk and nipples from females that are matched in lactation age. This result is discussed in terms of recip- rocally adaptive mechanisms between lactating females and their newborn offspring.""© 2015 Elsevier Inc. All rights reserved."