74 SWINE PRACTICl!. 



PHYSIOLOGIC CONSIDERATION 

 Digestion 



By digestion is ordinarily meant the bringing into solution of 

 materials that are consumed as food. Swine, in their natural state, 

 feed from substances obtained by rooting, the feeds consisting of 

 roots, nuts, etc. For this purpose, nature provided swine with a 

 long snout, well supported, and a lower lip that is pointed and 

 rather mobile. By breeding and selecting and providing ample food, 

 the structure of the swine snout has been altered. The natural 

 habit of rooting is readily prevented by ringing. 



The prehension of food by swine is accomplished by means of the 

 snout and lower lips, the teeth of swine are not well adapted for 

 grazing. The mastication of food by swine is not thorough, as they 

 usually swallow the food almost as rapidly as it is prehended. The 

 esophagus of swine permits the passage of relatively large masses, 

 which further relieves the necessity of thorough mastication. 



Gastric digestion of meats and allied products is not as perfect in 

 swine as in carnivorous animals, and the digestion of vegetable sub- 

 stances is not as perfect in swine as in herbiverous animals. Tlie 

 food is not completely mixed in the stomach for several hours and, 

 according to investigators, the type of digestion differs in the cardiac 

 and pyloric portion of the stomach. In the cardiac portion of the 

 stomach, starch is converted into sugar by the action of saliva. 

 Lactic fermentation is also occurring at the same time. Digestion 

 of albumin occurs in the pyloric portion of the stomach but usually 

 does not begin until three or four hours after consumption of food 

 and continues for several hours thereafter. 



Bile is secreted in quantities ranging from 1000 to 1200 grams 

 per day. There are no digestive ferments in the bile of swine, but 

 it has the ]iroperty of emulsifying fats. Bile of swine is greenish 

 yellow or yellowish brown, is odorless and alkaline in reaction. 



The pancreas of swine, as in other animals, apparently has periods 

 of rest, during which no pancreatic juice is secreted. While active, 

 this gland produces from five to ten grams of pancreatic juice per 

 hour. Pancreatic juice contains ferments that digest fats and albu- 

 minous substances and that also emulsify fat. Intestinal digestion, 

 therefore, includes the peptonization of albuminoids, the conversion 

 of starch into sugar and the emulsification of fats. The reaction 

 of the first portion of the intestine in swine is acid and the latter 



