FUNCTIONS OF THE NUTRIENTS 



177 



during mastication which was not given off promptly. 

 The Zuntz method of measuring the increase of oxygen 

 consumption would seem to be the more reliable. 



The results of Kellner and of Armsby and Fries, which 

 follow, do not appear to ratify the conclusions of Zuntz 

 and Hagemann, although the work of mastication was not 

 determined as a separate factor. 



259. Total energy expended in feed consumption. — 

 Extensive determinations of the total energy expended 

 in feed consumption have been made, both by Kellner 

 and by Armsby and Fries. The use of energy in this direc- 

 tion is determined by comparing th^ heat production of 

 two rations of unlike quantity, heat production being 

 equivalent to the energy expenditure by the animal. 

 The increased heat production for the larger ration should 

 be credited, therefore, to the increase of material in the 

 ration, whether a single feed or a mixtiu-e of feeds. 

 Residts by Armsby and Fries follow: 



Tasue XXXVII 



The "remainder," after deducting from the total 

 heat production that caused by standing, rising, lying 



Note. — ^In a recent publication by Armsby (Pennsylvania State 

 College Bulletin No. 142) the position is emphatically taken that the 

 consumption cost with concentrates is as great as with coarse feeds, and 

 suggests other factors which obscure differences caused by unlike 

 mechanical work. 



