324 PRINCIPLES OF FEEDING FARM ANIMALS 



Factors Affecting the Value of the Manure. — There are 

 various factors affecting the value of the manure, among 

 which may be mentioned the following: the feeds in the 

 ration, the age of the animal, the species of animal, loss 

 of the liquid manure, and losses by leaching and fermenta- 

 tion. 



Feeds in the Ration. — Of course the more nitrogen, phos- 

 phorus, and potassium there are in the ration the more there 

 will be in the excreta and, consequently, the more valuable 

 is the manure. Thus manure from a ration of corn and 

 timothy hay is not nearly as valuable as manure from a 

 ration of corn, cottonseed meal, and alfalfa hay. In general, 

 the use of feeds high in nitrogen and mineral matter greatly 

 increases the value of the manure. 



The age of the animal has an effect upon the value of the 

 manure. The young animal will store considerable of the 

 nitrogen, phosphorus, and potassium of its ration in the 

 form of new tissue or growth, while the mature animal 

 excretes all that is not used for maintenance. Also the 

 manure from a milch cow is less valuable than the manure 

 from a beef animal on the same ration because the milch 

 cow excretes a part of the nitrogen, phosphorus, and 

 potassium in her milk, while the beef animal excretes all 

 above the requirements for maintenance and growth in the 

 manure. 



The species of animal has considerable effect upon the 

 value of the manure. According to Van Slyke ^ the manure 

 of the different farm animals contains the following per- 

 centages of nitrogen, i^hosphorus, and potassium : 



1 " Fertilizers and Crops," p. 291. 



