118 SWINE 



The making of a hog may be compared to the building 

 of a brick house. In order to build such a house most 

 economically and most durably it must contain good ma- 

 terial and the proper amount of the various materials 

 that enter into the structure. These must also be prop- 

 erly used. 



Thus in the making of the body of a hog, if the best 

 results are to be obtained, the proper kinds of materials 

 must be brought into the structure, as well as the proper 

 amounts of the various kinds of these which must be 

 handled by the mechanism of the animal in the best possi- 

 ble working condition. It is true that the animal can sub- 

 stitute to some extent and use carbohydrate in place of 

 ether extract ; fat when obtained direct from the feed to a 

 slight degree in place of carbohydrate; and can use pro- 

 tein to some extent in place of carbohydrate or fat for 

 energy and heat production. He cannot, however, substi- 

 tute anything for the protein that is used for the regular 

 protein metabolism, neither for the water or the mineral 

 matter that is necessary for the proper making of the 

 animal body. Thus if a man who knows little or nothing 

 about feeds, about animals, and about feeding, can feed 

 hogs and obtain a fair degree of success how much greater 

 ought not such success to be if the man were properly 

 trained in these respects? The principal constituent parts 

 of the body of a hog are water, protein, fat, and ash or 

 mineral matter. 



WATER. 



About one-half of the live weight of the hog is water. 

 The amount of water, however, in the carcass depends 

 considerably on the condition of the animal. A thrifty, 

 growing hog that is not very fat will contain proportion- 



