PRINCIPLES OP FEEDlNCi POULTRY 



to have any very important influence in the digestion of 

 food. The crop in pigeons of both sexes is divided into 

 two parts and secretes a milky fluid for a few days after 

 their young are hatched which is used to feed their 

 squabs. 



DIGESTION AND ASSIMILATION OF FOOD 



The food passes from the crop into the preventriculus 

 or true stomach where it is acted upon by a gastric or 

 stomach juice. Gastric juice is an acid fluid which con- 

 tains enzymes and acids. The chief ferment of gastric 

 juice is pepsin which in the presence of acids changes the 

 protein into soluble nutrients. Thence the food goes into 

 the gizzard which is a powerful grinding organ. This has a 

 strong, rough lining in which the food is finely ground by 

 the action of small pieces of sharp sand or gravel called 

 grit. 



The small intestines continue the digestive system from 

 the gizzard and are looped around an elongated gland 

 called the pancreas. Next comes the liver and the bile, 

 the former being quite a large organ. The pancreas 

 secretes juices which are essential digestive fluids and 

 these act upon the protein, fats and carbohydrates, reduc- 

 ing them to simpler food forms. The liver has very im- 

 portant functions in regulating and assisting the digestive 

 processes by acting as a regulator on the carbohydrates. 

 The carbohydrates are stored up temporarily in the form 

 of glycogen through the action of the liver and supplied 

 to the system when needed for nourishment. The food 



27 



