1895.] 



PUBLIC DOCUMENT — No. 33. 



147 



The Excreta of ax Animal, — avhat they are. 



The fpeces are nothing more than the undigested portions of 

 the food. They are the portions that have resisted the action 

 of the various secretions of the stomach and digestive fluids 

 and bacteria of the intestines, and are consequently excreted 

 by the animal as so nuich Avorthless material. The urine is 

 entirely distinct from the fjeces. It contains the water and 

 the end products of the digestion of the nitrogenous portion 

 of the food, — the urea and hippuric acid, — which have 

 been removed from the blood by the kidneys. It also con- 

 tains about one-third of the phosphoric acid and nearly all 

 of the alkalies of the food consumed that have not been 

 retained in the animal's system, and small quantities of other 

 materials that it is unnecessary to consider in this connection. 



How the Digestible Matter of a Food is determined. 



First ascertain the amount and composition of the food 

 consumed by an animal in a given length of time, also the 

 amount and composition of the faeces or undigested portion 

 excreted in the same time on the basis of dry matter. The 

 difference between them will represent the amount of the 

 various constituents of the food digested. 



The percentages of the constituents digested are called the 

 digestion coeflScients. 



A Single Illustration^ showing hoiv the Digestibiliti/ of a 



Fodder is determined. 



[Solid manure equals the undigested part of food.] 

 English Hay. 



