Mimicking natural nursing conditions promotes early pup survival in domestic rabbits

In the wild rabbit, Oryctolagus cuniculus, mother-young relationships are b ased on restricted, once-per-day nursing interactions. Correspondingly, pup s have evolved an efficient strategy of energy saving. Here we investigate under breeding conditions, whether matching or not, the once-daily nursing visit by the rabbit females has an effect on pup survival and growth. Two n ursing regimen were applied to 89 primiparous (P) and to 78 multiparous (M) does: (a) one that matched the once daily nursing pattern (closed nest-box during the whole day except for a few minutes devoted to nursing) and (b) one that did not match it (24 h free nest access). In P females, the contro lled nest access resulted in lower mortality between birth and weaning (8.1 %) as compared to the free nest-access (18%). This effect was recorded from postnatal d 3-4 onwards. Both treatments induced different death causes (s tarvation (63%) in controlled-access regimen, and wounds and nest-soiling ( 29%) in free-access regimen). While both experimental nest-access regimens differentially affected pup survival in P or M females, they were without i nfluence on pup growth rate in does of either parity. It is concluded that repeated nest visits by the female increase risks of injury to pups, and of out-of-time pup activation or sucking, and that, more generally, it plays against the ethophysiologigal strategy of biomass conservation evolved by r abbit newborns. The fact that the nest-access regimen no longer affected pu p survival from the second parity suggests that the behaviour of multiparou s does more adequately models the offspring demands.