Maternal Deprivation in the Rat: Prevention of Mortality by Nonlactating Adults

Abstract

Rat litters were permanently deprived of their mother at age 13 days, and some were housed with a male or virgin female. Although over 90% of the adult-deprived pups died between 18 and 21 days of age, most mortality was prevented by the presence of a nonlactating adult. Survival could be attributed largely to the opportunity for tactual contact between pups and the adult, even though a significant amount of mortality could be prevented even by housing maternally deprived pups with a female from whom they were separated by a double wire screen. Postmortem examinations at 17 days disclosed that maternally deprived litters housed with and without adults did not differ in weight, skeletal growth, or presence of solid food in the stomach. Pups without adults retained more urine than those housed with adults. However, no renal damage was found, and direct stimulation of urination did not prevent mortality.