| Abstrakt: |
EXPERIMENTS on progeny of rats that were diet-restricted during gestation and lactation; on pups from rats diet-restricted during gestation only and on the offspring of rats who were subjected to no dietary restriction at all, lead to the following conclusions: 1. Dietary restriction of the dam during both pregnancy and lactation produces offspring who show high infant mortality (40 to 70%), permanent growth stunting (20 to 30%), greatly delayed development, increased feed intake per unit of body weight, behavior abnormalities such as excitability and exaggerated fear responses, abnormal social behavior and impaired learning ability. All of these occur despite the feeding of an adequate diet after weaning. 2. Dietary restriction of the dam during pregnancy only produces offspring who show an infant mortality rate indistinguishable from that of progeny of well-fed dams, growth stunting of about 5% and only moderate delays in development. However, behavior abnormalities are present as shown by tremors, circling, hyperexcitability and exaggerated fear responses. Learning is also impaired. All of this work has been done by a 50% overall dietary restriction. Experiments are now in progress to test the effects of feeding protein of low quality for the rat (such as wheat gluten) at an “adequate” level and of restricting calories onlyúnot protein. Results of the research in rats indicate that the nutrition of the mother rat during pregnancy and lactation is of the utmost importance in setting the pattern for the subsequent growth, rate of development, survival, behavior and intellectual performance of her offspring even though unlimited food of good quality is available to these pups after weaning. |
