Models of infantile malnutrition in rats: effects on maternal behavior.

The effects of 6 commonly used methods for producing malnutrition in suckling rats upon the behavior of their dams were examined. In these methods, (1) large litters were fostered on the dams; (2) dams were fed low-protein diets; (3) dams were fed an inadequate amount of a good quality diet; (4) pups were removed from the dams and kept with a nonlactating female for half of the day; (5) pups were removed from the dams and kept in an incubator for half of the day; or (6) some of th dams' teats were destroyed. Dams that were themselves food deprived showed a shift from resting to exploratory behaviors with some indication of increased attention to the pups compared to controls. Dams whose pups were starved but that were well fed themselves showed lower levels of resting and higher levels of attention to pups but no elevation in exploratory activity. Although the long-term significance of the behavioral changes of the dams is not known, the immediate effect was to minimize the impact of the experimenter's manipulations on the metabolic energy available to the pups for growth and development.