MATERNAL BEHAVIOUR IN THE RAT: SOME PARAMETERS AFFECTING THE ACCEPTANCE OF YOUNG DELIVERED BY CAESARIAN SECTION

Abstract

Summary. Rat offspring were delivered by Caesarian section at term and fostered to lactating mothers which had had their own young removed. The major variables studied were the presence or absence of the placenta at the time of fostering, the rate of presentation of the foster young to the mother, and the length of time a mother was without any young. The percentage of animals surviving until weaning (21 days) and the body weight of the survivors were recorded. The presence of the placenta at fostering resulted in a decrement in survival probability. The time that the foster mother was without pups and the rate at which foster pups were presented to the mother had an interactive effect: the highest survival rate was obtained when pups were presented 5 min apart to mothers which had had their own young removed 60 min before fostering.