SOURCES OF FAT IN ANIMAL BODY 535 



Ellis and his group 48 - 50 - 53 - 92-95 at the U. S. Department of Agriculture, as 

 well as from the investigations of Anderson and Mendel. 49 



(a) The Relationship of the Linoleate Content to the Type of Fat Ingested. 

 Ellis and Isbell 92 reported that the lards from hogs fed on a corn -f- skim 

 milk ration (4.5% fat) or on a brewer's yeast + tankage ration (1% fat) 

 were "hard," and had iodine numbers of 59 and 53, respectively. In 

 contradistinction to these results, the fat from hogs on a peanut diet was 

 "soft," while that from hogs receiving soybeans was graded as "oily" and, 

 in one case, had an iodine value 92 as high as 101. The "peanut lard" 

 appeared to resemble peanut oil much more than the "soybean lard" re- 

 sembled the soybean oil. 92 



The most marked variation in composition between the "hard" and 

 "soft" lards was in their linoleic acid content. Whereas this dienoic acid 

 accounted for only 1.9% of the total fatty acids in the first case, the 

 amounts were greatly increased in the "soft" types, reaching a maximum 

 of 30.6% in one sample from a hog which had received the soybean regi- 

 men. To compensate for this change in composition, there was a marked 

 decrease in the proportion of saturated acids; these averaged 38% of the 

 total in the "hard" samples and only 26% in the "soft" lards. In all 

 cases, a similar palmitic acid: stearic acid ratio of 2:1 obtained. It was 

 concluded that the primary cause of the softening was the presence of the 

 increased proportion of linoleate. » 



Ellis, Rothwell, and Pool 53 demonstrated that the deposition of linoleic 

 acid in the tissues was governed by different laws when cottonseed oil was 

 the food fat than when corn or soybean oils were ingested. In the first 

 case, the increase in the amount of linoleate which appeared in the hog fat, 

 as the proportion of cottonseed oil in the diet was augmented, was at the 

 expense of the oleic acid fraction; the saturated fats remained practically 

 constant. When increasing linoleate deposition occurred with higher 

 concentrations of corn oil, the oleic acid remained constant but the satu- 

 rated acids dropped proportionally. Spadola and Ellis 50 found that the 

 increased linoleate laid down in rats when cottonseed oil was fed was at 

 the expense not only of the oleic acid but also of the palmitoleic acid, which 

 comprises an important fraction of the unsaturated acid in this species. 

 Practically no difference in total saturated acids obtained between rats 

 which received a fat-low diet (saturated acids, 37.4%; linoleate, 0.0%) 



93 O. G. Hankins and N. R. Ellis, U. S. Dept. Agric, Dept. Bull. No. 1407, 1-68 

 (April, 1926). 



94 O. G. Hankins, N. R. Ellis, and J. H. Zeller, U. S. Dept. Agric, Dept. Bull. No. 1492, 

 1-50 (Feb., 1928). 



96 N. R. Ellis, U. S. Dept. Agric. Tech. Bull. No. 368, 1-14 (July, 1933). 



