304 POULTRY PRODUCTION 



ill solution proteins display' a mucilaginous character wliich is 

 made use of in the commercial ghies and mucilages. 



The most familiar exami)le of a mixture of vegetable 

 proteins is the gluten of wheat. The protein content of 

 whi-At a\erages a little less than 12 per cent and of corn a 

 little o\er 10 ]X'r cent. Most of the common whole grains 

 dc])a,rt very little from these figures. While some of the 

 grain liy-j)roducts such as wheat middlings (17.S per cent) 

 and gluten feed (25.4 per cent) have a considerably liiglier 

 percentage, they are usually fed in rather limited cpiantities. 



Table XXXV. — CoMro.9iTiON of Fowl and Ego.' 



Water, 

 per cent 

 Legh(jrn hen, entire fowl . 55.8 



Matiire Plymouth Rock, capon 41.6 

 New-laid egg (entire) . . 65.9 



New-laid egg (without shell) 74.45 

 White of egg 86.2 



Yolk . 48.03 



Dry matter in lien . .... 



Dry matter in entire egg .... 



Dr"\' 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 almost al\va>'s in the same mutual j)roportion as in water 

 (IIjO). They are plentiful in plants, appearing usually in 

 the form of sugar, starch, or cellulose As protein pre- 

 dominates in the fowl's bod,^■, so carbohydrates predominate 

 ill the structure of the plant. 



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

 stitute the common portable carbohydrate building material 

 (if ])lunts. Starch is the form in which most 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 

 with 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 wliich constitutes the greater 



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

 are not always in exact agreement. 



