CHAPTER XI 



NUTRITION OF POULTRY 



Nutritive requirements. Poultry need the food constituents used 

 by all creatures, but not always in the forms and proportions in 

 which they are used by other domestic creatures. The composi- 

 tion of the flesh of poultry does not differ greatly from that of 

 domestic animals used as food. In general it contains more protein 

 and less fat. 1 The rapid growth of poultry, however, demands a 

 larger proportion of concentrated food and relatively larger quan- 

 tities of food than other domestic creatures, and in birds which 

 lay nearly all the year round the heavy demand for concentrated 

 food is continuous. For both growth and egg production mineral 

 matter also is required in much larger proportion than in the diet 

 of mammals. 



Nutritive organs. The digestive organs of poultry present the 

 same general characteristics as those of mammals, varied in the 

 different kinds in accordance with their feeding habits and diet. 

 Briefly, they consist of a mouth, furnished with horny lips (beak, 

 or bill) ; a gullet ; an esophagus, having an enlargement (the crop) 

 in which the food taken in at the mouth is retained for some time 

 and subjected to action of the secretions of the crop ; a stomach 

 (the proventriculus), where the food received from the crop is 

 mixed with the gastric juice ; a gizzard, a muscular organ with 

 corrugated inner surfaces of tough, horny skin between which the 

 food is reduced before passing into the intestines ; large and small 

 intestines ; liver ; gall bladder ; pancreas ; two caeca ; rectum ; 

 cloaca ; and anus, or vent. In a study of poultry culture special 

 interest attaches to the mouth, crop, and gizzard, to the func- 

 tions of these organs, and to their relations to feeding theories 

 and practice. 



1 " Poultry as Food," FaivnerS Bulletin No. 182, United States Department of 

 Agriculture, also Bulletin No. 270, Storrs Agricultural Experiment Station. 



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