266 POULTEY CULTURE 



gen. The body utilizes the small amount of nitrogen needed 

 to replace wear and tear or nitrogenous tissue waste, growth, 

 and egg production and excretes the remainder, principally in 

 the form of uric acid, by the kidneys. Protein is not a source 

 of muscular energy, but increased muscular effort must be 

 met with an increased amount of protein in the feed to make 

 good nitrogenous tissue waste. Heavy egg production and 

 growth must be met with increased protein content of the 

 food. 



The non-nitrogenous food nutrients are carbohydrates and 

 hydrocarbons. The nutrients constituting the carbohydrate 

 group are starch, sugar, cellulose, and gum. As discussed 

 under digestion, these must be digested — that is, rendered 

 soluble, and in a form capable of being absorbed and assimi- 

 lated. They are probably all converted into one form of 

 sugar — ^namely, glucose, and as such are absorbed. Protein, 

 in splitting up in the body in the process of cell metabolism, 

 forms a nitrogenous and non-nitrogenous portion. The non- 

 nitrogenous portion of the protein adds to the carbohydrate 

 group in the body. It is capable of being transformed into 

 glycogen. 



In the body tissues the carbohydrates are readily oxidized. 

 It will be seen that in dextrose, which has a chemical formula 

 of C12H24O12, that the molecule contains enough oxygen to oxi- 

 dize the hydrogen after the disintegration of the carbohydrate 

 molecule. It, therefore, need only draw from the tissues 

 oxygen for the oxidation of the carbon. This is quite differ- 

 ent from what we will see in the fats and oils or hydrocarbons, 

 where the oxygen is far too small to oxidize all the hydrogen 

 of the molecule. Therefore, the fats need to obtain oxygen 

 from the tissues for the oxidation of all the carbon and a 

 greater part of the hydrogen. 



One gram of carbohydrate requires 50.8 cubic inches of 

 oxygen, which produces 50.8 cubic inches carbon dioxid 

 (CO2), while 1 gram fat requires 17.6 cubic inches of oxygen, 

 which produces 87.5 cubic inches carbon dioxid. 



Carbohydrates are one source of muscular energy. Com- 

 bustion takes place during muscular contraction. As a result 

 of this oxidation, heat and energy are both produced. The 



