182 THE POTATO. 



CHAPTER XX. 



POTATOES AS POULTRY FOOD. 



ALTHOUGH potatoes are, as generally used, not a good food 

 for the feathered stock, as a supplementary vegetable diet 

 they may be turned to good account by the intelligent, 

 poultry-keeper. The tuber, as everyone knows, is mainly 

 composed of starch and water. Over fifty per cent, of its 

 bulk consists of the latter, the remainder being starch, 

 with just a trace of flesh-forming material, and no fat or 

 oil. Starchy or carbonaceous foods, such as the potato, 

 are mainly of use in maintaining the heat of the body 

 they are the fuel necessary for the combustion that is ever 

 going on in the processes of digestion and assimilation. 

 Then there is that other group of foods termed nitrogen- 

 ous, which exists in animal matter and albumen, and is 

 present in the seeds and leaves of plants ; but it is only to 

 a very small extent contained in potatoes. This nitrogen- 

 ous matter is mainly of use in the building up of muscle, 

 bone, and tissue, and in repairing the waste that is ever 

 going on in the body. The white of an egg is nearly pure 

 albumen, or is nitrogenous in its composition. Now, a 

 proper diet should consist of the right proportions of nitro- 

 genous and carbonaceous foods, which has well been called 

 a " nutritive ratio," and that proportion should be, under 

 normal conditions, one part by weight of nitrogenous 

 matter to four parts of carbonaceous. Much depends, of 

 course, upon the condition of the birds, the weather or 

 temperature, method of housing, extent of liberty allowed, 

 and whether the birds are expected to produce eggs or to 

 lay on fat and flesh. If a carbonaceous diet is fed to ex- 



