FACTORS ALTERING NUTRITIONAL VALUE 911 



In a later study Boer and co-workers^"' reported that rapeseed oil diets 

 were decidedly inferior to regimens containing biitterfat in stimulating 

 groAvth. This finding has been confirmed by Deuel and associates, ^'^ as 

 well as by Euler, Euler, and Lindeman.^^ The latter workers also found 

 margarine superior to rapeseed oil in stimulating growth. Undoubtedly 

 the low growth-promoting activity of rapeseed oil in the rat is associated 

 with its poor digestibility in this species.''^ 



The preponderance of experimental evidence would seem to indicate 

 that satisfactory growth is obtained with a variety of vegetable oils, equal 

 to that observed with butter. Thus Deuel and co-workers"^ observed that 

 the extent of growth in rats during the first twelve weeks after weaning was 

 the same, irrespective of whether butterfat, corn, cottonseed, olive, peanut, 

 or soybean oil, or a vegetable margarine fat, was chosen as the source of 

 fat. In these latter experiments rancidity was prevented by refrigeration 

 of the food and by the addition of tocopherol to the diet. The fact that 

 the similar gains-in-weight obtained after the administration of the diets 

 containing the several vegetable fats and butter represent true groAvth was 

 confirmed by measurement of the bone length, "^ as well as by the demon- 

 stration that the body composition of the animals was similar in these 

 several groups."^ Euler, Euler,and Saberg"* likewise reported that butter 

 exhibits no superiority over margarine insofar as growth-promoting proper- 

 ties in the case of rats is concerned. In fact, these workers observed better 

 growth when rats were fed diets containing margarine than when butter 

 served as the source of dietary fat. In later reports,"^ the comparison of 

 the growth on butter and on margarine w^as extended to twenty-six months; 

 growth was found to be equally satisfactory with the two fats over the 

 entire period, although the individual weights of the offspring were higher 

 on the butter diet. Deuel and co-workers,"^ Zialcita and Mitchell,"^ 



«>' J. Boer, B. C. P. Jansen, and A. Kentie, /. Nutrition, S3, 339-358 (1947). 



510 H. J. Deuel, Jr., S. M. Greenberg, E. E. Straub, D. Jue, C. M. Gooding, and C. F. 

 Brown, /. Nutrition, 35, 301-314 (1948). 



"1 B. V. Euler, H. v. Euler, and G. Lindeman, Arkiv. Kem. Mineral. Geol, B 26, No. 

 3,1-5(1948). 



312 H. J. Deuel, Jr., E. Movitt, L. F. Hallman, and F. Mattson, /. Nutrition, 27, 107- 

 121 (1944). 



313 H. J. Deuel, Jr., L. F. Hallman, E. Movitt, F. H. Mattson, and E. Wu, /. iVu^n- 

 iio?i,;?7, 335-338(1944). 



31^ B. V. Euler, H. v. Euler, and I. Saberg, Ernahrung, 7, No. 3, 65-74 (1942). 



3's B. V. Euler, H. v. Euler, and I. Ronnestam-Siiberg, Arkiv. Kemi, Mineral., Geol, A 

 :^^, No. 8, 1-12(1946). 



»i6 H. J. Deuel, Jr., S. M. Greenberg, E. E. Straub, T. Fukui, C. M. Gooding, and C. 

 F. Brown, /. Nutrition, 38, 361-368 (1949). 



»'' L. P. Zialcita, Jr., and H. H. Mitchell, Science, 100, 60-62 (1944). 



