20 FEEDS AND FEEDING 



The large intestine, into which the small intestine empties, is larger 

 in diameter, but much shorter. In cattle the large intestine has a capac- 

 ity of about 40 quarts, in sheep 6 quarts, and in hogs 11 quarts. In 

 the horse, the part of the large intestine next to the small intestine, 

 called the blind gut, or caecum, is greatly enlarged and the large colon, 

 the second part of the large intestine, also is much larger than in cattle. 

 Due to this, the large intestine in the horse has a total capacity of 120 

 to 140 quarts, partially making up for the small size of the stomach. Were 

 it not for the great size of the caecum and of the large colon, the 

 horse would be unable to consume and digest much hay or other rough- 

 age. 



The pig has neither the four stomachs of the ruminants nor the large 

 caecum of the horse and is therefore not well fitted to use large amounts 

 of roughage. His large intestine, however, holds nearly twice as much 

 as that of the sheep, which aids him somewhat in utilizing coarse feed. 



36. Mastication. In the mouth the food is crushed and ground by the 

 teeth and at the same time moistened by the alkaline, somewhat slimy, 

 saliva. In the mastication of food moist and slippery masses are formed 

 which pass readily thru the gullet into the stomach. Exceedingly 

 large amounts of saliva are secreted by the larger farm animals, es- 

 pecially when eating dry feed. For example, a horse may secrete as 

 much as 90 Ibs. during 24 hours. Colin 2 found that oats required a little 

 more than their own weight, green fodders half, and dry hays or fod- 

 ders four times their weight of saliva during mastication. The sensation 

 of taste is largely dependent on the saliva, as it dissolves small amounts 

 of food, which affect the nerves of the tongue that are concerned with 

 this sensation. 



Ruminants while eating chew their food only enough to moisten it, if 

 dry, and form it into masses of suitable size to be swallowed. When 

 hunger is satisfied they seek a quiet place, if possible, and proceed to 

 return the food in "cuds" to the mouth, chewing each thoroly before 

 reswallowing. The gullet of ruminants, which passes to the third 

 stomach, or many plies, also opens into the paunch and the honeycomb 

 thru a slit (called the esophageal groove). This has an exceedingly 

 important function in the process of rumination. The masses of solid 

 food which ruminants swallow are usually .so large as to distend the 

 gullet. On coming to the slit they are therefore pressed out, just as 

 would be the case if one tried to force thru a rubber tube with a slit 

 an object which fitted it tightly. These masses of food are usually pushed 

 into the paunch until it is full, and then into the honeycomb instead. 



When the animal ruminates, or "chews the cud," the food is forced 

 back to the mouth in masses, or "cuds," thru the same slit by contrac- 

 tions of the muscular paunch, the honeycomb, and of the gullet itself. 

 The ox chews each cud of about 4 ounces for a little less than a minute, 

 adding saliva until the finely divided material becomes more or less soup- 

 like. On being reswallowed, this finely divided material may flow along 



2 Smith, Physiol. Domestic Animals, p. 286. 



