Onset of puberty and duration of fertility in rats fed a restricted diet.

Chronic dietary restriction such that the body weight of CFY Sprague-Dawley female rats was 50% that of animals fed ad libitum resulted in enhanced longevity (LD 50 of 1090 days compared to 704 days). All the experimental females had reached puberty by 227 days and 80% were able to conceive and wean young at 510 days, an age beyond that at which the control rats had ceased to breed (450 days). Some (25%) of the experimental rats were able to breed at over 800 days of age.