Maternal Protein Deprivation during Pregnancy or Lactation in Rats and the Efficiency of Food and Nitrogen Utilization of the Progeny

Both prenatal and postnatal malnutrition were imposed upon rats by feeding pregnant dams a low protein diet, or after either normal or malnourished pups were born, feeding a low protein diet to the dams they were suckling for the first 3 weeks of life. A second period of postnatal malnutrition was imposed on some rats by feeding a low protein diet for 4 weeks to pups after they were weaned at 3 weeks of age. Among the physiological and biochemical effects that were found to persist for at least 6 months after a postnatal exposure to protein-calorie malnutrition, the following observa tions were made: 1) There was a permanent stunting of growth for those rats mal nourished the first 3 weeks, but not for those malnourished from week 3 to 7 of life. 2) Growth hormone administration from week 3 to 7 in normal rats or for the first 4 weeks of nutritional rehabilitation was without effect upon growth rate or ultimate body weight. 3) There was a decreased efficiency of food utilization that persisted during rehabilitation and after growth had plateaued. 4) Food utilization was improved by growth hormone. 5) Postprandial oxygen consumption was higher in previously mal nourished rats than in normal controls. 6) In the adult, previously malnourished rat there was an increase in nitrogen retention (increased biological value) over that obtained in normal controls when 10% protein as wheat gluten was fed and this was true for all periods of postnatal malnutrition that were studied. No change in nitrogen retention due to previous malnutrition was found when the dietary protein was casein. 7) In all of the physiological and metabolic studies reported above, no changes were observed in those animals that had been malnourished during the period of gestation alone. These long-lasting effects appear to be caused specifically by postnatal nutritional deprivations. J. Nutr. 103: 273-284, 1973.