CHAPTER III 

 THE DIGESTION OF FEEDS 



THE farm animals that chew their feed a second time are known 

 as ruminants. Cattle, sheep, and goats belong to this class. The 

 non-ruminants, on the other hand, are represented among the farm 

 animals by the horse and the pig. The two kinds of animals differ 

 radically in the anatomy of their digestive apparatus ; the stomach 

 of the ruminants consists of four divisions or sacs, of which the 

 first three are mainly reservoirs for softening and holding the feed 

 till it is returned to the mouth to be chewed again, while the fourth 

 one is the true stomach, where a digestive fluid is secreted. The 

 non-ruminating animals have only one stomach, into which the 

 feed passes directly from the mouth and the gullet (oesophagus), 

 and is acted upon by the digestive fluid secreted there. We shall 

 consider separately the digestive apparatus of ruminants and non- 

 ruminants. 



The digestive apparatus of ruminants consists, as already 

 stated, of four separate compartments that are connected with one 

 another, viz.: 



a. The rumen or paunch. 



b. The reticulum or honeycomb. 



c. The omasum or manyplies. 



d. The abomasum or the true stomach (Fig. 7). 



The first three stomachs are mainly enlargements of the ali- 

 mentary canal and serve as reservoirs for the feed before it is 

 chewed the second time. The rumen or paunch is by far the 

 largest one of the four stomachs and, in the case of grown cattle, 

 holds about nine-tenths of the total capacity of them all. The 

 abomasum, or fourth stomach, corresponds to the single stomach 

 of the non-ruminants, and, like this, contains a digestive fluid which 

 acts upon the feed. When the cow swallows her feed, which is 

 partly chewed and well mixed with saliva, it passes down the gullet 

 and partly into the paunch through a slit in the gullet, partly into 

 the second stomach (honeycomb). It remains here for a time 

 and is softened by the saliva and the watery secretions of the 

 paunch wall. The contents of the paunch are given a churning 

 motion which gradually forces it toward the funnel-shaped orifice of 

 the gullet through compression of the paunch by the diaphragm 

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