Body Composition and Fat Depot Weights of Rats as Influenced by Ration Fed Dams during Lactation and That Fed Rats after Weaning

Publisher Website
Google Scholar
Abstract
Litters of Osborne-Mendel (OM) pups were reduced to eight each at birth and suckled by OM dams; the latter were fed either a high fat (60% w/w) or a grain (3% fat, w/w) ration during lactation. The pups of these dams at 21 days of age are identified as F and G, respectively. F rats were heavier, had more body protein, water and fat and heavier subcutaneous fat depots than G pups (P < 0.01). Half of the remaining F pups of both sexes and of weights similar to those killed were fed, after weaning, the high fat rations. They were designated FF; the other half were fed the grain ration and designated FG. Likewise G pups fed the high fat ration were designated GF while those continued on the grain ration were designated GG. Five or six rats of each sex from each of the four diet groups were killed at 42, 84 and 168 days of age, at which time fat depots were weighed and each carcass was analyzed for protein, fat, moisture and ash. FF and FG rats tended to be heavier and had more body protein and fat and had heavier fat depots than GF and GG rats, respectively, but this was not significant. Statistical significance occurred only when the rats in the upper and lower percentiles were evaluated for each of the above parameters. The upper 20% always contained more FF rats and the lower 20% more GG rats. These data suggest that in a strain of rats such as the OM which readily becomes obese when fed a high fat ration, the nature of the diet fed after weaning has a profound effect on the ultimate obesity of the animal which completely overshadows the effect of dietary intake during the first 3 weeks of age.