128 



MAITUAL OF CATTLE-FEEI)IE"G. 



ratus, were mucli more readily oxidized iix tlie body tlian 

 before. 



§ 3. Feeding with Pbotbin alone. 



In order to obtain a clear idea of tlie various factors 

 wliicli determine the consumption of protein, on tlie one 

 hand, and its deposition on the other, it will be best, in 

 the first place, to consider the phenomena produced when 

 the several nutrients are fed alone, and afterward the 

 effect of two, or of all of them together. 



Consumption dependent on Supply. — The numerous 

 researches made by Voit ^ have shown most fully that 

 the consumption of jwotein in the hody is largely deter- 

 mined ly the stijtply of protein in the food. That the ex- 

 cretion of urea, and consequently the protein consumption, 

 was influenced by the food to a very considerable extent, 

 had ah'eady been noticed, but this observer has the merit 

 of having fully investigated the subject and given it the 

 prominence it deserved. His experiments were made 

 chiefly on dogs; the following are some of the results 

 obtained in different experiments on the same dog with 

 a diet of various quantities of pure, fat-free meat : 



Meat oaten por day , 

 tTroa excreted 

 Correspcmdmg to flesn 



Grms. 



Grms 

 800 



Grms 

 500 



Grms 



Grms 

 1,200 



Grms. 

 1,500 



Grms 

 2,000 



Grms 

 2,500 







900 



12 



32 



40 



08 



88 



10*6 



144 



173 



105 



442 



552 



9S8 



1,214 



1,463 



1,987 



2,387 



Grma. 



2,C)b{) 

 181 



2,4% 



The consumption of flesh varied from 165 grms. per 

 day during hunger to nearly 2,500 grms. with the largest 

 amount of albuminoids in the food, and almost exactly in 



* Zeitaclinft f. Biologie, III., 1. 



