166 



THE FEEDING OF ANIMALS 



in which the ground hay is burned under pressure in the 

 presence of pure oxygen, and the heat evolved is all 

 used in warming a known weight of water. Data are thus 

 obtained from which it is possible to calculate the Calories 

 in the particular material burned. The energy Value of 

 single compounds, such as albumin, starch, and sugar, 

 may also be found in the same way, as has been done in 

 a large number of instances. These data show that the 

 heat resulting from the combustion of the compounds of 

 a given class is not the same in all cases. The value in 

 large Calories of one gram of several pure nutrients is 

 shown in the following table: 



Table XXVIII 

 Proteins 



Calories Calories 



Wheat gluten . 5.99 Egg albumin .... 5.73 



Gliadin . 5.92 Muscle (pure) . . . 5.72 



Glutenin 5.88 Blood fibrin . . 5.64 



Plant fibrin 5.94 Peptone . . ... 6.30 



Serum albumin . . 5.92 Wool. . . . 5.51 



Milk casein 5.86 Gelatin 5.27 



Yolk of egg . . 5.84 Asparagin (amide) . 3.45 



Cabbohtdkates Fats 



Calories Calories 



Starch . . 4.18 Of swine 9.38 



Cellulose 4.18 Of oxen . 9.38 



Glucose ... . 3.74 Of sheep . 9.41 



Gane-sugar . . . 3.95 Maize oil 9.28 



Milk-sugar 3.95 Olive oil . . . 9.47 



Maltose . . 3.95 Ether-extract of oats . 8.93 



Zylose ... . 3.74 Ether-extract of barley 9.07 



The heat values of a gram of the dry substance of 



various cattle foods, which is a mixture of the several 

 nutrients, were found by recent determinations to be the 

 following, expressed in calories: 



