318 POULTRY PRODUCTION 



Besides secreting the bile, an eminently necessary contri- 

 bution to digestion, the liver of the goose has been demon- • 

 strated by Minkowski (as quoted by Brown^ to be the seat 

 of much of the synthesis of the uric acid that escapes 

 in the urine. It is also the seat of the manufacture of 

 glycogen, a carbohydrate whose function is to furnish energy 

 to the muscles throughout the body. 



Intestine. — The walls of that portion of the intestine which 

 forms the duodenal loop probably secretes no digestive fluids. 

 Further on it secretes a fluid (succus entericus) which con- 

 tains erepsin and the invertases. Erepsin is an enzyme which 

 carries to a conclusion the work of digesting the protein. 

 The invertases are . enzymes which have the power of 

 converting more or less complex sugars into simple ones, 

 capable of absorption. 



It will be noticed that there has been no provision for the 

 digestion of crude fiber. So far as the all too few digestion 

 trials show, crude fiber is almost entirely undigested by 

 chickens and geese. In the first three compartments of the 

 stomach of ruminants and in the cecum of the horse, bacteria 

 have an opportunity to act on crude fiber. 



With fowls, however, bacteria have little opportunity for 

 action. As soon as the hard-coated grains become moist 

 and soft enough for bacterial action, the material passes 

 down the gullet to the proventriculus, where the acid reaction 

 checks bacterial action. After passing the gizzard to the 

 intestine the reaction becomes so markedly alkaline as 

 to inhibit their development. The time spent in the short 

 rectum, which corresponds to the large intestine in larger 

 animals, is so limited and the uric acid from the kidneys 

 so plentiful that bacterial growth is again inhibited. 



Besides its digestive function, the small intestine also 

 acts as an organ of absorption, as does also the rectum to a 

 certain degree, taking in the soluble nutrients and inorganic 

 salts. 



Ceca. — At the juncture of the intestine and the rectum are 

 two blind pouches, given off from either side, called ceca. 



' Bureau of Animal Industry, Bulletin No. 56. 



