256 POULTRY CtTLTURE 



The reaction of the stomach or proventriculus contents is 

 strongly acid, Ukewise the same holds good of the gizzard. 

 The reaction of the contents of the duodenum or first portion 

 of the small intestines is weakly acid ; of the latter part of the 

 small intestines, faintly acid, neutral, or faintly alkahne. The 

 same holds good for the ceca. The reaction of the large intes- 

 tine or rectum is alkaline. 



The pancreatic secretion is influenced by special secretory 

 nerves. The food, after undergoing a reduction to fineness 

 in the gizzard, is povu-ed out into the duodenum or first portion 

 of the small intestines. The wall of the intestine is lined by a 

 mucous membrane which is provided with secreting tubular 

 glands. Certain cells of these glands secrete a substance 

 known as an internal secretion which, when absorbed, causes 

 a stimulation of the pancreatic cells to activity and the pan- 

 creatic fluid is poured out into the small intestines. 



The pancreatic secretion is one of the essential digestive 

 fluids. It acts upon all three organic groups of food nutrients. 

 Its three enzymes and their action are as follows : 



Trypsin, a proteolytic enzyme which acts upon proteids 

 (protein) . 



Steapsin (hpase), a hpolytic enzyme which acts upon fats 

 (hydrocarbons).- 



Amylopsin, a diastatic enzyme which acts upon the carbohy- 

 drates (starches, sugars). 



The proportion of these ferments apparently vary with the 

 character of the food taken in by the fowl. If the food con- 

 sumed is rich in starch, the secretion will be rich in diastatic 

 ferment; if protein, then rich in proteolytic enzyme. 



The trypsin, as it comes from the pancreas, contains a sub- 

 stance called trypsinogen, which is a precursor of trypsin; 

 another substance is secreted by the cells of the glands of the 

 small intestine and is called enterokinase. This enterokinase 

 acts upon the trypsinogen converting it into trypsin. The 

 trypsin is apparently the only one of the three ferments that 

 is secreted in an inactive state and necessitates being activated. 



All foodstuffs must be reduced to a more simpler form than 

 they appear in vegetable and animal tissues. As seen under 

 the discussion above, the protein molecule is complex. Tryp- 



