910 EXPERIMENT STATION RECORD. 



was formed from starch, 51.07 gm. of carbon dioxid was produced at 

 the same time. For this no oxygen from the air was required. The 

 amount of carbon dioxid produced by the formation of* 5.412 gm. of 

 fat would therefore be 0.28 gm. If the 0.3 gm. of digestible crude fiber 

 be neglected and the total nitrogen in the urine be regarded as derived 

 from the cleavage of protein, since the rice fed contained practically 

 no nonprotein nitrogen and the total protein content was small, the 

 respiratory quotient of the pig may be calculated as follows: The 

 oxidation of protein required 1.23 gm. of oxygen, producing 1.3G gm. of 

 carbon dioxid. The fat formed from starch required no oxygen and 

 produced 0.28 gm. of carbon dioxid. The oxidation of starch required 

 10.01 gm. of oxygen and produced 13.70 gm. of carbon dioxid. The 

 total oxygen required was therefore 11.24 gm. and the total carbon 

 dioxid produced was 21.40 gm. The respiratory quotient would be 

 21.40-^ 1.96G 33_ 10.88 _ n 

 H.24-^1.43003 - TM~ ' 



A fasting pig weighing 141 kg. excreted 9.8 gm. of nitrogen in the 

 urine and 217 gm. of carbon. At a weight of 71 gm. the pig would 

 have produced more carbon dioxid, in the proportion of \/li¥: v'TT 2 , 

 since the metabolism of small animals is intense and the cleavage 

 (Stoffumsatz) is equal to the cube root of the square of the live weight. 

 Of the 217 gm. of carbon in the expired air, 191.8 gm. came from the 

 cleavage of fat, the cleavage of protein causing 9.8 gm. of nitrogen in 

 the urine, which would have necessitated the excretion of 25.2 gm. of 

 carbon in the breath as carbon dioxid (217—25.2 = 191.8). In the case 

 of the pig weighing 71 kg. the oxidation of 2.15 gm. of carbon from fat 

 and 0.282 gm. of carbon from protein furnished the energy expended 



/191.8x27.1' \ 



per kilogram of live weight f — \±\ x 17 - 15 = 2 * 15 )• 



As noted above, the oxidation of 1 gm. of carbon from fat liberates 

 12.4 calories. Therefore 2.15 gm. of carbon from fat would furnish 26.7 

 calories; and 0.282 gm. of carbon from protein would furnish 2.8 calories 



(jTl X 4.1x0.282 = 2.8 ). Therefore the energy per kilogram of live 



weight would be 20.7+2.8 = 29.5 calorics. 



In the case of the pig fed 2,000 gm. of rice the oxygen utilized in 

 the oxidation of protein was 1.23 gm., or 0.80 liters; that is, 0.906 gm. 

 of protein was oxidized and 3.7 calories of energy was produced 

 (0.900 x 4.1 = 3.7). In the same experiment 10.1 gm., or 7 liters, of oxygen 

 was required for the oxidation of starch, and this furnished 35 calories 

 7x5 = 35). Further, 6.28 gm., or 3.2 liters, of carbon dioxid was pro- 

 duced as an accompaniment of the fat formed. As noted above, this 

 furnished 3.68 calories (3.2 x 1.15 = 3.68). The total energy liberated was 

 therefore 3.7+35.0+3.7 = 42.4 calories. The 3.7 calories furnished by 

 the formation of fat played no part in the labor of digestion. Deduct- 

 ing this amount from the total (42.4) leaves 38.7 calories. The energy 



' 27.1 = l^ 141- ; 17.15 = &7V. 



