234 POULTRY BREEDING AND MANAGEMENT 



Palatability. It has been pertinently said that it is pos- 

 sible to make a mixture of wet leather and a petroleum 

 jelly that would give the same result as meat by the ordin- 

 ary food analysis. Palatability comes in here. Leather and 

 petroleum jelly would scarcely be as palatable as meat, nor 

 would it be expected that the one would give as good an 

 egg yield as the other. 



Again, while a high digestibility of food is important, 

 yet digestibility is not a certain measure of the value of 

 the food. Sherman in "Chemistry of Food and Nutrition/' 

 says: "Foods similar in chemical composition and equally 

 well digested, may or may not be of equal nutritive value, ' ' 

 and again : ' l The coefficient of digestibility is but little in- 

 fluenced by the palatability of the food." 



Summing Up. We have here three factors there may 

 be others that must be taken into account in arriving at 

 the true value of a food ; namely, composition, digestibility 

 and palatability. While any of these factors, standing 

 alone, may not mean much to the feeder, no one of them 

 must be disregarded. In proportion as his knowledge cov- 

 ers all three factors he will be able to feed intelligently; 

 but after all the knowledge that comes from practical feed- 

 ing experiments is all important and necessary to a com- 

 plete knowledge of the value of any particular ration. 



Digestive Organs. The organs of the fowl concerned 

 in digestion of food are shown on p. 235. This photo- 

 graph shows the various organs beginning with the man- 

 dibles or beak used for picking up food. The tongue moist- 

 ens the food with saliva, after which the food passes 

 through the esophagus, or gullet, on the way to the crop, 

 where it remains about 12 hours. The food is here soften- 

 ed and then passes into the stomach where it is mixed with 

 gastric juices and passes on into the gizzard. The gizzard 

 is the largest organ of the hen, and its office is to crush or 



