1172 THE PEOPLE'S FARM AND STOCK CYCLOPEDIA. 



Foods. Vegetable foods, which are what we have to do 

 with in feeding animals, are composed of five principal sub- 

 stances, which resemble the four chief constituents of the ani- 

 mal. These are: Water; Carbohydrates, substances of the 

 nature of starch and sugar, which contain no nitrogen ; Fats, 

 composed of the same elements as carbohydrates, but containing 

 a larger proportion of carbon; Albuminoids, substances com- 

 posed of carbon, hydrogen, oxygen, and nitrogen, and nearly 

 identical in composition with the nitrogenous matter of the ani- 

 mal body; Ash, that which remains when a plant is burned. 

 It contains phosphate of lime in considerable proportion, and 

 supplies the material for the formation of bones. 



We thus see that the plant is exactly fitted for the support 

 of animal life. A more detailed description of the composition 

 of various foods will be given later in this chapter. 



Use of Food. Food in the animal body is used for six 

 different purposes : 1. The repair of waste; 2. Growth; 3. Pro- 

 duction of milk ; 4. Production of fat ; 5. Maintaining animal 

 heat; 6. Supplying energy. 



The body is constantly undergoing waste. The substance 

 wears out, breaks down, is taken up by the blood, and removed 

 by the excretory organs namely, kidneys, lungs, and skin. 

 The matter thus removed must be as constantly replaced, or the 

 animal will grow thin, and ultimately die. To supply material 

 for repairing this waste is the first use of food. 



When an undeveloped animal is given more food than is re- 

 quired for repair of waste and for supplying heat and energy, 

 the additional material is used for the production of more tissue, 

 and the animal grows. If no more food is supplied than is 

 required for the first, fifth, and sixth uses, the animal can not 

 grow, but becomes stunted. 



When a mature animal is supplied with more food than is re- 

 quired for repair of waste and production of heat and energy, 

 the surplus material is converted into fat. It is much more dif- 

 ficult to make a young animal lay on fat than a mature one; for 

 if the food is of the right character it will use the surplus in 

 growth, rather than in production of fat. 



