STATICS 123 



and the fuel value of the urea from 4 Ibs. of protein digested 

 is [0-872 X 4=] 3'488 kt. 



(3) Experiments in the respiration chamber show that 

 3*17 Ibs. of methane are formed from each 100 Ibs. of pure 

 starch. The fuel value of methane is 13*34 kt. per Ib. The 

 fuel value of the methane from i Ib. of starch is, therefore, 

 [ J 3'34 X 3*17 -f- ioo =] 0-423 kt. and the fuel value of the 

 gases from 41 Ibs. of digested carbohydrates is [0-423 X 41 =] 

 f7*34 kl 



(4) The fuel values of the dung 160-95 kt., the urea 

 from the digested protein 3*488 kt., and the gases from the 

 digested carbohydrates 17*34 kt. are now to be added 

 together and subtracted from the total fuel value of the food. 



364-43 181-78 = 182-65 kt. 



The available energy of the food is, therefore, 1-83 kt. 

 per Ib. 



The fuel value of the urea from i Ib. of protein is 

 [2-542 X 0-343] 0*872 kt. The available energy of the 

 protein is, therefore, [5*8 0*87 = ] 4*93 kt. per Ib. 



The fuel value of the methane from i Ib. of starch is 

 [13-34 X 0*0317 =] 0-4229 kt. The available energy of the 

 starch is, therefore, [4*1825 0*4229 =] 3*76 kt. per Ib. 



As there are no by-products from the fat, the available 

 energy is the same as the total fuel value, viz. 8*5 kt. per Ib. 



By applying these factors to the digestible constituents, the 

 same result as before is obtained more directly, thus 



182-18 



The available energy of the food is, therefore, 1*82 kt. 

 per Ib. 



Loss of Heat. In the case of non-pregnant animals in 



