30 PRINCIPLES OF FEEDING FARM ANIMALS 



It contains three different ferments : ( 1 ) Erepsin, which acts upon the 

 decomposition products of the proteins, albumose and peptones, in the 

 same way as trypsin; (2) an amylolytic -ferment which converts starch 

 to sugar (maltose), and (3) invertases (sucrase, maltase, and lactase), 

 changing the di-saccharides, cane-, malt-, and milk-sugar, into mono- 

 saccharides (dextrose or glucose, see p. 14). 



From the small intestines the undigested material passes into 

 the large intestine, where the formation of the solid excrements 

 takes place. The ferments and bacteria, present here in immense 

 numbers, continue their action until the mass has assumed the con- 

 sistency peculiar to each species and is voided as faeces. 



Summarizing the various steps in the digestion of the different 

 components of feed, we note that 



Starch is changed into sugar (maltose) by the ptyalin of the 

 saliva, the amylopsin of the pancreatic juice, and an amylolytic fer- 

 ment in the intestinal juice. 



Fats are changed into free fatty acids and glycerin by the lipase 

 of the pancreatic juice, and by the bile into emulsified fats or soaps. 



Proteins are changed into proteose and peptones by the pepsin of 

 the gastric juice, and into amino bodies by the trypsin of the pan- 

 creatic juice and the erepsin of the intestinal juice. 



In addition to the action of these various digestive ferments the 

 feed is subjected to bacterial action in the paunch and the intes- 

 tines. Through the fermentation processes caused by bacteria, the 

 cellulose and considerable quantities of other carbohydrates are de- 

 composed and converted into gaseous products, like marsh gas, 

 carbon-dioxide, and free hydrogen, which are of no value to the ani- 

 mals except incidentally through the heat generated in these proc- 

 esses; this may be of benefit in aiding to maintain the body 

 temperature of the animals. 



Digestion of Feed by Non-ruminants. The digestion of feed 

 by the non-ruminating farm animals takes place, as previously 

 suggested, in much the same way as in the case of the ruminants. 



The same digestive fluids act on the feed of the horse and other 

 animals of this class as in the case of the ruminants, viz., saliva, 

 gastric juice, pancreatic juice, bile, and intestinal juice. These 

 differ from the corresponding fluids secreted by ruminants mainly 

 in point of concentration. The protein compounds are broken up 

 into simple soluble substances, like peptones and amino acids; the 

 starch is changed into maltose, and the fats into free fatty acids, 

 emulsified fats, or soaps. The stomach of the horse has a capacity 

 of 12 to 15 quarts, while the paunch of a cow or steer holds over 

 100 quarts. The horses cannot, therefore, eat as much of bulky 



