PART IV 



FEEDING 



CHAPTER XX 



ELEMENTS OF THE BIRD'S BODY AND 

 COMPOSITION OF ITS FEED 



CHEMICAL analysis shows a close similarity between 

 the composition of the bird's body and the composition of 

 its feed. This similarity is chiefly apparent in the kinds of 

 material present. Different feeds vary greatly in their 

 composition. Birds of different ages, and of different breeds, 

 also vary in their structural elements. Yet materials vary- 

 ing in composition and especially suited to the different 

 requirements of feeding may be found. A general knowledge 

 of the composition of the birds, and of available feeds, is 

 necessary in compounding a practical ration. Birds generally 

 are of active temperament, and endowed with great energy. 

 This temperament and energy mean the consumption of 

 a large amount of materials to produce heat. They also 

 have an extremely high body temperature, which in turn 

 calls for feed of a certain composition. They also yield 

 products whose heavy weight is out of all proportion to 

 their body weight. This explains why the laying hen con- 

 sumes so much more feed than the one which does not lay. 



COMPOSITION OF THE BIRD'S BODY 



The bodies of all animals, birds included, consist of four 

 well defined groups of elements, commonly classed as pro- 

 tein materials, fatty materials, ash, and water. The following 

 discussion will tell us something about these materials, and 

 the amounts thereof which are found in the body (Fig. 121). 



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