CHAPTER XVIII. 

 Feeds and Feeding. 



Food is that which is taken into the body of animals and is 

 transformed into tissues, heat and energy. 



Composition. 



Food as usually purchased consists of the edible portion and 

 the refuse. The edible portion consists of water and the nu- 

 trients-protein, fats, carbohydrates and mineral matter or ash. 



The refuse consists of shells, bones, entrails and other parts 

 not used for food. 



The chief use of water in its relation to foods is to act as a 

 solvent and to aid in the digestion of foods. 



Water constitutes about 75 per cent of the weight of animal 

 bodies and growing plants. 



Chief Functions of Principal Foods. 



Protein builds and repairs tissue. 

 Fats are stored for the production of energy. 

 Carbohydrates furnish fat and energy. 

 Mineral matter Or ash helps to form bone. 



Composition of Foods. 



Protein consists of the white of eggs, casein of milk, lean 

 meat, gluten of wheat. 



Fats are derived from meat, butter, olive oil, oil of corn. 



Carbohydrates consist of crude fiber, starch, sugar, gum, 

 resin. 



Mineral matter consists of potash, soda, and other minerals. 



The composition of different samples of the same kind of 

 food is not uniform in amount. 



The same kind of plant will vary in composition in different 

 localities, according to soil, maturity and characteristics. 



(328) 



