310 . POULTRY PRODUCTION 



cent.) have a considerably higher percentage, they are 

 usually fed in rather limited quantities. 



Table XXVII. — Composition of Fowl and Egq.^ 



Water, 

 per cent. 

 Leghorn hen, entire fowl . . 55 . 8 

 Mature Plymouth Rook, capon 41.6 

 New-laid egg (entire) . . . 65 . 9 

 New-laid egg (without shell) 74 . 45 



White of egg 86.2 



Yolk .... . 48.63 



Dry matter in hen . . .... 



Dry matter in entire egg . .... 



Dry matter in entire egg aside 



from shell . 49.8 3.5 38.6 



Carbohydrates. — Carbohydrates are compounds of carbon, 

 hydrogen, and oxygen, in which the hydrogen and oxygen 

 are always in the same mutual proportion as in water (H2O). 

 They are plentiful in plants, appearing usually in the form of 

 sugar, starch, or cellulose. As protein predominates in thfe 

 fowl's body, so carbohydrates predominate in the structure 

 of the plant. 



The sugars are soluble in the juices of the plant and con- 

 stitute the common portable carbohydrate building material 

 of plants. Starch is the form in which plants store their 

 reserve. It serves much the same function for plants as 

 does fat for animals. The starch stored in the kernel of 

 corn and the potato tuber are familiar examples. It is 

 witji this form of carbohydrate that the feeder of poultry 

 has most to do, forming as it does from 50 to 75 per cent, 

 of the feed of vegetable origin. 



Cellulose is that substance which constitutes the skeleton 

 or framework of plants. In poultry feeding it is usually 

 referred to as crude fiber and will be throughout this work. 

 It constitutes from 2 to 5 per cent, of seeds and grains. 

 Because of the fact that crude fiber is comparatively un- 

 digestible, the rest of the carbohydrates are distinguished 

 collectively by the term nitrogen-free extract. 



Carbohydrates, which are so plentiful in plants, are 

 scarcely found in the fowl's body or the egg. Glycogen, 



' The analyses recorded in this table are from several different sources and 

 are not always in exact agreement. 



