COMPOSITION 0-^ MANUEB ^15 



The proportion of the ash constituents of the food 

 "which is stored up in the body of an animal is gener- 

 ally very small. In the case of the fattening animals, 

 96 per cent., or more, of the ash constituents of the 

 food find their way into the manure ; but with young 

 growing animals the proportion retained in the body is 

 much more considerable. 



With fattening oxen and sheep, and with horses, 

 more than 95 per cent, of the nitrogen of the food are 

 voided in the manure. The pig is seen to retain a 

 larger proportion of the nitrogen of its food, about 

 85 per cent, appearing in the manure. The milking 

 cow gives a still better return in saleable produce for 

 the nitrogen which it receives, only about 76 per cent, 

 appearing in the manure. The best return is in the 

 case of the young calf fed on milk, only 30 per cent, of 

 the nitrogen consumed appearing as manure. These 

 proportions are, of course, exactly true only in the 

 case of the diets assumed to be given to each animal ; 

 with diets containing a smaller amount of albuminoids 

 the proportion of nitrogen appearing as manure will be 

 diminished. 



The amount of nitrogen voided in the urine is seen 

 to be always greater than the quantity contained in 

 the solid excrement, and in the case of fattening 

 animals it may be three or four times as much. This 

 relation will vary according to the character of the 

 diet. If the food is nitrogenous, and easily digested, 

 the nitrogen in the urine will greatly preponderate ; if, 

 on the other hand, the food is one imperfectly digested, 

 the nitrogen in the solid excrement may form the 

 larger quantity. When horses are fed only on poor 

 hay, the nitrogen in the solid excrement will somewhat 



