54 Feeds and Feeding. 



Carbon, Nitrogen, 



grams. grams. 



Digested from the food 765.37 18.67 



Outgo in respiratory and excreted products... 476.15 12.59 



Eemaining in the body of the animal 289. 22 6. 08 



The surplus of nitrogen corresponds to the formation of 38 

 grams of protein, (58) containing 20. 1 grams of carbon; there is 

 then left for the formation of fat from the carbon surplus 269.12 

 grams. This would be contained in 269.12x1.3, (58) or 349.9 

 grams of fat. The total quantity of fat in the food amounted to 

 7.9 grams, so that if this was digested and deposited in the body, 

 342 grams of fat must have been formed from other sources. The 

 nitrogen excreted as urea. showed a decomposition of 65.4 grams 

 of protein in the body of the animal. This quantity of protein 

 could at best form no more than 65.4 x .514, (78) or 33.6 grams 

 of fat, leaving 308.4 grams of fat deposited in the body to be 

 derived from carbohydrates. Seven to eight times as much fat, 

 therefore, originated from this source as could have been formed 

 from the protein and the fat in the food. 



The formation of fat from carbohydrates in the nutrition of 

 ruminants, especially cattle, is conclusively proved by the results 

 of experiments conducted by G. Kiihn during 1882-90. ^ 



77. rormation of fat in milk. — Collier^ has shown in the case of 

 a herd of pure-bred cows that the fat in the food was sufficient to 

 account for the fat produced ia the milk during all but the first two 

 months of their lactation period. The average ratio of fat in food 

 to fat in milk for the whole period of lactation for all cows 

 was 121 : 100. It should be remembered, however, that the fiat 

 in the food consumed by the cows was not wholly digested, and 

 was, moreover, the "crude fat" or ether extract of chemical 

 analysis. This extract contains chlorophyll and other impurities 

 dissolved from the fodders by the ether in the process of analysis. 

 Allowing 17.4 per cent, for impurities. Collier says there is still 

 enough fat in the food to account for the fat recovered in the milk. 



The experiments with mUch cows have not given as decisive 



» Landw. Vers„ 44, pp. 1-581. 

 •N. Y. Expt. Station (Geneva), 



1891, p. 124. 



