THE FEED PROBLEM 



253 



When these groups of nutrients are taken into the body of 

 the bird they are converted from vegetable tissue or substance 

 into animal tissue through digestion, absorption, and assimila- 

 tion. This process we know as the process of nutrition. 



Distribution of the Bioelements (From Hackh) 



Element 



Per cent. 



in 

 mammal 



Per cent, 

 in carbo- 

 hydrate 



o.. 

 c. 



H.. 



N.. 



Ca. 



P.. 



K.. 



S.. 



CI. 



Na. 



Mg 



I... 



F.. 



Fe. 



Br. 



Al. 



Si.. 



Mn 



49.38 

 44.44 

 6.18 

 0.00 

 0.00 

 00 

 0.00 

 00 

 0.00 

 0.00 

 0.00 

 0.00 

 0.00 

 0.00 

 0.00 

 00 

 0.00 

 0.00 



100.000 I 100.00 



Per cent, 

 in 



fat 



17.90 

 69.05 

 10.00 

 0.61 

 0.00 

 2.13 

 0.00 

 0.31 

 0.00 

 0.00 

 0.00 

 0.00 

 0.00 

 0.00 

 0.00 

 0.00 

 0.00 

 0.00 



100 . 00 



protein 



22,40 

 51.30 

 6.90 

 17.80 

 0.00 

 0.70 

 0.00 

 0.80 

 0.00 

 0.00 

 0.00 

 0.00 

 0.00 

 0.01 

 0.00 

 0.00 

 0.00 

 0.00 



Per cent, 

 in fresh 



water 



100.00 



88 . 800 

 0.005 



11.160 

 0.002 

 0.004 

 0.001 

 0.001 

 0.018 

 0.000 

 0.001 

 0.003 

 Remainder 

 0.000 

 0.002 

 0.000 

 0.000 

 0.000 

 0.000 



100.000 



THE PHYSIOLOGY OF DIGESTION 



Digestion in the fowl is rapid. Experiments show that food 

 will pass through the intestinal tract of a 2-pound chick in 

 about three hours, of a laying hen in thi-ee hours and in a hen not 

 lajdng in about eight hours and in a sitting hen in f oiu-teen hours. 

 All test material had passed through the intestines by the end 

 of seventy-two hours. All tests were run on an empty crop. 



The food is taken in by the bird by its prehensile organs, 

 which passes through the first portion of the esophagus to the 

 crop or ingluvius (Fig. 98, letters a, b^, and 6^). 



