CHAPTER XIV. 

 FARMYARD MANURE. 



i. Nature and Composition of Farmyard Manure. 



A large amount of food consumed by a horse, cow, or 

 other animal undergoes digestion in the stomach and 

 intestines, being changed in the process into various 

 chemical substances, which are absorbed into the blood 

 stream, and carried to different parts of the body where 

 growth is going on, or where the repair of tissues is 

 needed. As a result of the vital activity of the organism, 

 its substance is continually being broken down into waste 

 products which must be removed or excreted from the 

 body if healthy life is to be preserved. The fats and 

 carbohydrates taken in are oxidised to water and 

 carbon dioxide gas, the latter escaping into the air from 

 the lungs in the act of breathing. The nitrogen of the 

 proteins in the food and wearing tissues ultimately 

 appears as urea and allied soluble nitrogenous substances 

 which are excreted in the urine. The sulphur and phos- 

 phorus in nutrient materials are oxidized, and leave the 

 body as alkaline sulphates and phosphates partly in the 

 solid faeces and partly in the urine along with other 

 dissolved salts. The undigested material passes along 

 the intestinal canal, and is evacuated as faeces or dung. 



Farmyard manure is composed mainly of three con- 

 stituents, namely : 



(1) The faeces or dung, and, 



(2) The urine, 



