132 AGRICULTURE. 



^.— KINDS OF iJ"OOD. 



I. Nitrogenous Foods. 



Those supplying nitrogenous compounds, or 

 protein, which are used in the formation of tis- 

 sues — as, muscle, bone, hair, horn, and also of 

 blood and milk — must be furnished to promote 

 the growth of the growing animal. 



II. Carbonaceous Foods. 



Those — as, starch and sugar — which supply the 

 carbohydrates and fats are necessary to produce 

 the heat and energy of the body. If there is 

 an excess of this kind of food over that required 

 in producing heat and energy it is stored in the 

 body as fat, and may be drawn upon at any time 

 when the food does not contain sufficient heat- 

 producing elements. 



III. Other Elements. 



There are other elements necessary to a com- 

 plete food, but they are always contained in suf- 

 ficient quantity in all foods which supply the 

 necessary protein, carbohydrates, and fats, so do 

 not need to be taken into consideration in the 

 selection of foods. 



C— COMPARISON OF NITROGENOUS AND 

 CARBONACEOUS FOODS. 



I. Protein. 



When the carbohydrates are lacking, heat and 

 energy can be produced by the protein of the 

 food, or even by the tissues, by flesh consump- 



