FEEDS AND FEEDING 83 



of the body. Besides furnishing material for tissue, it also con- 

 tains carbon and may be burned to form heat and energy, or 

 serve as a source of fats or carbohydrates in the materials fed, 

 containing a deficiency of such nutrients and an excess of 

 protein; but the production of fat, heat, and energy with protein 

 is very expensive. Therefore, as protein substances are always 

 the most expensive feeds, it never pays to feed an excess of 

 protein, such as is contained in cotton seed meal to cattle, beef- 

 scraps to chickens, and peas or scrap peanuts to pigeons. Be- 

 sides, an excess of protein is really injurious, producing an en- 

 largement of the liver, and a plethoric condition of the system, 

 generally. 



For these reasons, feeds very rich in protein should not be 

 fed alone, nor in too great proportions. 



Fats and Oils 



Fats and oils are used in the animal body as a source of fat 

 and also to furnish heat and energy. Animals require heat to 

 keep the body warm and energy to run the animal mechanism, 

 and do outside work. The beating of the heart, eating, breath- 

 ing, movement of the intestines, and the muscular movements, 

 such as the head, arms, legs, wings, require energy furnished 

 by the burning, or oxidation of fats, carbohydrates, or protein, 

 one pound of fat in the feed being equivalent to 2^/4 pounds 

 of carbohydrates. 



Value of Fats 



Fat ranks next to protein in value as a food element, or nu- 

 trient. The more protein and fat a certain class of feed stuff 

 contains, the better the quality, as compared with other feed 

 stuffs of the same class. Peanuts containing 58 per cent protein 

 and fats combined is more valuable than peanuts containing 

 only 48 per cent protien and fats combined. Two feed stuffs 

 of different kinds cannot, however, always be compared on the 

 basis of their protein and fat contents alone, for other factors 

 must be considered. 



Crude Fiber 

 Crude fiber is that part of vegetable feeds that resists the 

 action of acids and alkalis, and consists mainly of the cell walls 

 the woody fiber. It is the most indigestible part of food pro- 



