FARM MANURES 163 



retained from the more liberal ration, due to more 

 favorable conditions for growth. Because of this fact 

 there is present in the manure from the mixed feed one 

 half more nitrogen, and two and one half times as much 

 phosphoric acid, as in the manure from the timothy 

 hay, which, free from bedding, contains about 790 

 pounds of indigestible matter, while the manure from 

 the mixed feed contains 760 pounds, the mixed ration 

 being more digestible. If both manures contain the 

 same amount of absorbents, the manure from the ton 

 of mixed clover and bran will weigh slightly less, 

 but contain more fertility than that from the timothy 

 hay. 



The value of manure can be accurately determined 

 from the composition of the food consumed and the 

 care which the manure has received. Only a small 

 amount of the nitrogen in the food is permanently 

 retained in the body. The larger portion is used for 

 repair purposes, the nitrogen of the tissues which 

 have been renewed being voided as urea in the 

 liquid excrements. Some of the nitrogenous com- 

 pounds of the food are utilized for the production 

 of fat, in which case the nitrogen is voided in the 

 excrements. The fact that but little of the nitrogen 

 and mineral matter of the food, under most condi- 

 tions, is retained in the body is shown by the in- 

 vestigations of Lawes and Gilbert upon the compo- 

 sition of the flesh added to animals while undergoing 

 the fattening process. 55 



