300 



POULTRY PRODUCTION 



THE NUTRIENTS. 



Every constituent of the feed that can yield heat or energy 

 or can serve for the production of body tissue is called a 

 nutrient. All poultry feedstuFfs are composed of one or 

 more of the following groups of nutrients: (1) water, (2) 

 ash, (o) proteins, (4) carbohydrates, and (5) fats. For con- 

 venience, these nutrients may be classed as follows: 



Dry matter ■ 



Water (1) 

 (1) Ash (2) 



(2) Organic nutrieuta 



Inort^anic nutrients 



(1) Proteins 



(2) Carbohj'drates 



(1) Crude fiber 



(2) Nitrogen- 

 free extract 



(3) Fats 



Of these, water alone is a definite chemical compound. 

 Ash, [irotein, carbohydrate, and fats, which collectively 

 form the dry matter, are classes or groups of compounds 

 ha\-ing certain distinctive characteristics. 



Relation of the Nutrients to Production. — Both the fowl's 

 body and the egg are composed of the same five groups of 

 compounds. These compounds are not in most cases trans- 

 ferred directly as such from the feed to the tissues, but are 

 split up in the digestive tract, aljsorbed and rebtiilt into the 

 body. 



There is, however, a close relation between the nutrient 

 composition of the feed and its use in building tissue. The 

 ash in the body or in the egg can only come from the ash in 

 the feed. The protein of the body can be built up and the 

 protein of the egg claltorated only when protein of the proper 

 kinds is furnished in the feed. AVhile, as is shown elsewhere, 

 fat may be manufactiu'cd from ])rtitein, it is normally made 

 over from fats in the feed or built up from carbohydrate from 

 the same source. The \ery small amotuit of carbohytlrate in 

 the fowl's body and the still smaller amount in the egg 

 usually have the carbohydr.-ite of the feed as their original 

 source. 



