SCIENTIFIC SWINE FEEDING 253 



The carbohydrate roughages are all in the form of green 

 feeds and may be considered, in so far as water is concerned, 

 as green feeds under the head of nitrogenous roughages. 



SELECTION OF FEEDS 



Feeds should be selected primarily to furnish the proper 

 quantity of digestible nutrients in a palatable form as follows : 

 Water, protein, carbohydrates, ether extract, mineral matter, 

 and bulk. While some feeds may have values other than their 

 digestible nutrients, if a pig is properly fed, these are of minor 

 importance. Home-grown feeds should be used where pos- 

 sible, but where these are not available commercial feeds may 

 be substituted. While many of the commercial feeds are all 

 right and as good perhaps as those that may be grown on the 

 farm the profit in general is greater from home-grown feeds. 

 Furthermore, the supply of commercial feeds is limited and 

 available only to a comparatively small number of feeders. 



The carbohydrate feeds in general must be used to make up 

 the carbohydrate part of the ration and the nitrogenous feeds 

 to furnish the bulk of the protein. All carbohydrate feeds 

 contain some protein and most all nitrogenous feeds contain 

 some carbohydrate; consequently in the selection of the feeds 

 for a ration they should be combined in such quantities that the 

 proper amount of digestible nutrients is supplied. 



Water is found to a greater or less extent in all feeds. Those 

 classified as dry feeds usually contain only a small quantity — 

 from 8 to 18 per cent.; other feeds such as liquid feeds and 

 succulent feeds contain as high as 85 or 90 per cent, of water. 

 Since, however, these sources of water — excepting Uquid feeds 

 — are not sufficient, pigs must be fed water directly. 



A pig under five or six months of age apparently cannot as- 

 similate as much as it can digest; consequently best results are 

 obtained if it is not fed more than it can finally use for the 

 construction of body tissue and for energy and heat produc- 

 tion. In order to limit the nutrients to the amount that the 

 pig can most profitably use, roughages may be introduced 

 into the ration at this time. These serve a double purpose, 

 as already explained. 



