Comparative Reproduction and Lactation of Rats Fed Butter or Vegetable Fat Included in a Basal Ration Free of Animal Products

The effects of butter or butterfat have been compared with those of a hydrogenated vegetable fat product or the fat rendered from it in regard to reproduction and lactation of rats fed these fats over several generations in a basal ration free of any animal product. Fairly rigorous conditions of reproduction and lactation were used. In most respects, no significant differences were found among the various fats in regard to the various aspects of reproduction and lactation. Such differences as were observed were not large. In the F2 to F4 generations combined, average weaning weights of the young were found to be significantly higher for butterfat as compared to the hydrogenated vegetable fat but not for whole butter as compared to the whole vegetable fat product. Post-weaning weight gains of rats fed the two different fats or fat products differed by only 2 or 3% on the average. A comparison was also made between the weights of certain organs and glands of 11- to 12-week-old male rats fed the butter or vegetable fat rations. The inclusion of sulfathalidine in the rations failed to bring about any differences among these and other fats tested.