DIGESTIBILITY OF SOME ANIMAL FATS. 11 



Summary of digestion experiments with beef fat in a simple mixed diet. 



Exper- 

 iment 

 No. 



Subject. 



Protein. 



Fat. 



Carbohy- 

 drates. 



Ash. 



61 

 • 62 

 63 

 69 

 70 

 71 

 72 

 102 



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 



E.M 



64.2 



R.L. S 



60.8 



R. L. S 



50.0 



I. D. B 



45.1 



W. D 



59.8 



E. M 



56.8 



I. D. B 



61.5 



103 



W. D 



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 duo to a solution in tho fat of specific flavoring 

 bodies in the seasoning herb and the browned fruit and vegetable. 



Very littlo experiment nl work concerning tho digestibility of mutton 

 fat has been found. Grindley 2 in his studies of the effect of cooking 

 upon the digestibility of moats included among others a leg of mut- 



• U. s. Uept. Agr., Farmer ' Bui. 520(1012). 



» Loc. cit. 



