20 FEEDS AND FEEDING, ABRIDGED 



fat constitute the generally recognized classes of nutrients, altho air, 

 water, and mineral matter might likewise be so termed. 



The term digestible nutrient covers that portion of each nutrient 

 which may be digested and taken into the body. 



A ration is the feed allowed for a given animal during a day of 

 24 hours, whether all is fed at one time or in portions at different 

 times, 



A balanced ration is one which furnishes the several nutrients — 

 crude protein, carbohydrates, and fat — in such proportion and amount 

 as will properly nourish a given animal for 24 hours. 



The alimentary canal. — The alimentary canal is a long, tortuous 

 tube passing thru the animal from mouth to vent, enlarged in places 

 for the storage of food or waste. It includes the mouth, gullet, 



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Fig. 7. — Diagram of the Digestive Tract of the Cow 



A, Salivary glands; b, gullet; c, paunch, or first stomach (Only a small part 

 of the paunch is here visible, the rear portion being hidden by the intestines) ; 

 d, honeycomb, or second stomach; e, manyplies, or third stomach; f, fourth, or 

 true stomach; g, duodenum, or first part of small intestine; h, mesenteric part 

 of small intestine; i, caecum; j, colon; k, rectum; 1, point of entrance of bile 

 duct into duodenum; m, point of entrance of pancreatic duct into duodenum. 

 The intestines are spread out somewhat in this diagram. 



stomach, small intestine, and large intestine. Within its linings are 

 organs which secrete the various fluids of digestion, and into it, from 

 other organs located near by, pour still other digestive fluids. Within 

 its walls are nerves controlling its action, arteries which nourish it 

 with fresh blood, and veins and lymphatics which absorb and carry 

 from it the products of digestion. 



Ruminants (animals which chew the cud), including the ox, sheep, 

 and goat, have much more complicated digestive tracts than other 

 animals. In the horse and pig the gullet is a simple muscular tube 

 passing from the mouth to the stomach. In ruminants the gullet is 



