METABOLISM AND FOOD 73 



Daily ration. Decomposition Gain (-f) or 



Meat Starch. of protein loss ( - ) of 



(protein). in the body, body protein. 



500 gr. o gr. 564 gr. 64 gr. 



500 gr. 100-300 gr. 502 gr. - 2 gr. 



800 gr. o gr. 826 gr. - 26 gr. 



800 gr. 100-400 gr. 763 gr. + 37 gr. 



1000 gr. o gr. 1028 gr. - 28 gr. 



1000 gr. 100-400 gr. 902 gr. + 98 gr. 



2000 gr. o gr. 1991 gr. -f- 9 gr. 



2000 gr. 200-300 gr. 1792 gr. +208 gr. 



With the addition of protein to the diet the 

 nitrogen metabolism increased; when starch was 

 added a decrease in the metabolism was noticed, 

 and led to a storage of protein in the body. 



Further investigations have shown that the 

 quantity of protein which just suffices for an 

 animal can be considerably reduced if nitrogen-free 

 substances are fed with the protein. A dog 

 weighing 30 kilos (66 Ibs.) required 1200-1500 gr. 

 of lean meat in order not to lose body flesh ; if, how- 

 ever, fat (250 gr.) was given along with the meat, 

 then 500 gr. sufficed to prevent loss from the body. 

 In this connection it has been shown that the 

 minimum requirements in protein are astonish- 

 ingly low, when at the same time large quantities 

 of nitrogen-free substances are consumed. The 

 full-grown ruminant does not require to draw 



