312 



POULTRY PRODUCTION 



Nature provides 

 Worms, grubs, and 

 insects. 



Sprouts and grasses. 



Gravel. 



Water. 



■ It supplies 

 Protein. 



Carbohydrate (protein 

 and fat). 



Succulence' (water, car- 

 bohydrate, protein, 

 and fat). 



Ash and grit. 



Water. 



Producer feeds 

 Meat scrap, milk, 



oil 



meal, gluten, feed. 



The grains and their by- 

 products. 



Sprouted oats, mangle 

 beets, pasture, etc. 



Commercial grit, oyster 

 shell, granulated bone, 

 etc. 



Water. 



Mutual Relations of the Nutrients. — ^The elements, carbon, 

 hydrogen, and oxygen, are always present in all three of the 

 nutrients. These alone are found in the carbohydrates and 

 fats, and the practical difference between the two classes is 

 the greatly increased proportion of carbon in the case of the 

 fat. It has been found by careful experiment that fat has a 

 fuel and energy value about 2.25 times as great as does the 

 carbohydrate, principally because of this greater amount of 

 carbon. That is to say, a pound of fat will generate over 

 twice as much heat as a pound of carbohydrates, or will 

 furnish the power for more than twice as much muscular 

 effort. It may therefore be said to have a feeding value 

 2.25 times as great. 



It was shown by Voit and Lehmann (as reported by 

 Lusk^) , in experiments where rice was fed to geese, that almost 

 one-third of the carbon was retained in the bodies of the 

 geese in the form of fat, and that this fat must have been 

 built up out of the carbohydrate (starch). 



The great difference between the foregoing and protein is 

 the presence of nitrogen in the latter. While fat and carbo- 

 hydrate are mutually interchangeable in feeding practice 

 to a considerable extent, neither of them can be fed in the 

 place of protein. Protein, on the other hand, may to a limited 

 extent replace either or both of the other two. This is be- 

 cause of the fact that it contains all the elements to be found 

 in them (carbon, hydrogen, and oxygen), and by wasting the 



' Succulence is a form of feed containing a large amount of water, 

 page 329. 

 ^ Science of Nutrition. 



See 



