DIGESTIBILITY OP SOME ANIMAL FATS. H 
Summary of digestion experiments with beef fat in a simple mixed diet. 
Exper- 
iment 
No. 
Subject. 
Protein. 
Fat. 
Carbohy- 
drates. 
Ash. 
61 
W. D 
Per cent. 
86.4 
78.7 
76.9 
74.4 
62.4 
81.6 
75.5 
79.2 
69.0 
71.7 
Per cent. 
94.4 
93.8 
89.0 
85.6 
87.7 
91.2 
90.3 
87.3 
82.4 
87.5 
Per cent. 
97.4 
97.3 
97.4 
96.5 
95.4 
97.1 
96.5 
96.9 
95.6 
97.0 
Per cent. 
72.4 
62 
E.M 
64.2 
63 
69 
R.L. S 
R. L. S 
60.8 
50.0 
70 
71 
I. D. B 
W. D 
45.1 
59.8 
72 
E.M 
56.8 
102 
103 
I. D. B 
W. D 
61.5 
38.8 
104 
E.M 
52.3 
75.6 
88.9 
96.7 
56.2 
The' average value, 88.9 per cent, is the digestibility of the fat con- 
tent of the entire ration. However, this, it is believed, may be taken 
to represent the coefficient of digestibility of beef fat alone, inasmuch 
as this fat comprised over 97 per cent of the total fat content of the 
diet. The digestibility seemed to decrease with the decrease in the 
amount of fat consumed. One reason may be that the ether extract 
of the feces contains not only the undigested fat, but also some 
ether-soluble metabolic products. If it be assumed that the amount 
of metabolic products remained fairly constant in the different tests, 
there would obviously be a proportionately larger quantity present 
in the feces as the amount of fat consumed decreased. 
MUTTON FAT. 
That only small quantities of mutton fat are used in the United 
States for culinary purposes may be due partly to a smaller available 
supply, partly to its marked flavor, and partly to its relatively high 
melting point and corresponding hardness. The possibility of extend- 
ing its use was considered in work undertaken with reference to the 
use of mutton in the diet. 1 One method of utilizing mutton fat in 
cooking consists in mixing small quantities after rendering with 
softer fats, such as lard. The resulting mixture is somewhat softer 
than the mutton fat and may be used for various household purposes. 
It is possible to make a savory fat by heating the mutton fat at a low 
temperature with an onion or sour apple and a little summer savory 
or ground thyme until the onion or apple is thoroughly brown. The 
peculiar flavor seems to be masked by this process, the savoriness 
being quite likely due to a solution in the fat of specific flavoring 
bodies in the seasoning herb and the browned fruit and vegetable. 
Very little experimental work concerning the digestibility of mutton 
fat has been found. Grindley 2 in his studies of the effect of cooking 
upon the digestibility of meats included among others a leg of mut- 
U. S. Dept. Agr., Farmers' Bui. 526 (1913). 
2 Loc. cit. 
