DIGESTIBILITY OF MISCELLANEOUS ANIMAL FATS. 19 



Summary of digestion experiments with ox-marrow fat in a simple mixed diet. 





Experiment No. 



Subject. 



Digestibility of entire ration. 



Esti- 

 mated 





Protein. 



Eat. 



Carbohy- 

 drate. 



Ash. 



digesti- 

 bility of 

 ox-mar- 

 row fat 

 alone. 



692 



P. K 



Per cent. 

 68.3 

 69.2 

 31.5 

 67.9 



Per cent. 

 91.3 

 93.3 

 90.9 

 89.3 



Per cent. 

 97.8 

 97.8 

 96.9 

 97.2 



Per cent. 

 71.8 

 68.8 

 56.1 

 50.0 



Per cent. 

 93.7 



693 



J. C. M..' 



95.6 



694 



A. A. R 



91.6 



695 



W. E. T 



93.1 











59.2 



91.2 



97.4 



61.7 



93.5 











In the experiments reported above the subjects ate on an average 

 21 grams of protein, 89 grams of fat (of which 87 grams were mar- 

 row fat), and 340 grams of carbohydrate. This diet furnished ap- 

 proximately 2,245 calories of energy daily. It will be noted that in 

 experiment No. 695 the subject W. E. T., who did not possess a very 

 vigorous appetite, ate only 109 grams of fat during the three-day 

 period. The other subjects averaged 104 grams of fat daily. The 

 protein supplied by the diet was 59.2 per cent digested, the fat 

 91.2 per cent, and the carbohydrate 97.4 per cent. The figure 91.2 

 per cent for the digestibility of the total fat of the diet becomes 93.5 

 per cent for the digestibility of marrow fat alone when correction is 

 applied for the metabolic products and undigested basal-ration fat 

 which occurs in the ether extract of the feces. 



The consumption of 100 grams of marrow fat daily for a period of 

 three clays or more evidently caused digestive disturbances since 

 in experiment No. 692, subject P. K. reported : " Health was normal 

 when entering on the diet. During the period experienced a slight 

 headache and a sickish feeling." In experiment No. 693, subject 

 J. C. M. reported : " Felt a severe weakness accompanied by cold 

 perspiration." In experiment No. 694, subject A. A. E. reported: 

 " Pains in head and abdomen, general feeling of weakness." In ex- 

 periment No. 695, subject W. E. T. reported: " Health normal at start 

 of diet, during diet headache with general weak feeling." 



On the basis of these experiments alone, it would appear that the 

 continued consumption of 100 grams of marrow fat daily is likely to 

 be attended with physiological disturbances. The results of the ex- 

 periments indicate, however, that this fat is as completely digested as 

 the common animal and vegetable fats. 



OX-TAIL FAT. 



Ox-tail fat is separated and marketed as an edible fat to a small 

 extent at least in this country. In reply to an inquiry regarding its 

 commercial production, one food-packing concern states : " This fat 



