Maternal malnutrition and the neonatal environment.

Altered behavioral development was observed in suckling rats from dams fed a low protein diet either during gestation or during the lactation period. Lactational malnutrition markedly depressed all behaviors displayed by the suckling young. These included litter fragmentation, pup climbing, rearing, feeding, and drinking behavior. Although less severe, pups from a dam fed a deficient diet during gestation displayed the same altered behavioral development. Moreover, small birth weight pups born from well-nourished dams also showed delayed behavioral development. Contact with pups was increased in dams who were malnourished during the lactation period or who were nursing pups from dams malnourished during the gestation period. Results support in part the hypothesis that malnourished early in life "functionally isolates" the developing animal from its immediate environment.