304 THE FEEDING OF ANIMALS 



As these compounds exist in much smaller proportion in 

 grain, swine when confined to a restricted grain diet may 

 suffer from a lack of such accessory bodies. The addition, 

 therefore, to the grain food of swine of some green food, 

 such as alfalfa, would appear to insure the animal against 

 defective growth. 



Dairy by-products are carriers of both Fat-soluble A 

 and Water-soluble B, and the recognized value of these 

 by-products in pig-feeding is perhaps partly due to the 

 presence of these substances. As time proceeds, the 

 knowledge necessary to the compounding of rations with 

 reference to the growth-promoting value will doubtless 

 be greatly enlarged. 



402. Influence of ration on quality of product. The 

 rations should be compounded with reference to the 

 quality of the product. Our knowledge of the influence 

 of foods upon the quality of meat products is by no means 

 complete, but that food has an influence upon the flavor 

 of milk and upon the chemical and physical properties of 

 butter, seems to be fairly well established. 



403. Home supply of feeding-stuffs to be considered. 

 Rations should be compounded with reference to the 

 home supply of feeding-stuffs and to market prices. 

 Economy often demands that the materials in hand shall 

 be used even if the ration is not ideal. Again, there 

 are several protein foods which may be used, and it is 

 often only a question of price in determining which should 

 be purchased. Notwithstanding the claims of manu- 

 facturers, there is no one feeding-stuff essential to the 

 health of animals or to the highest quality of the pro- 

 duct, so that the feeder may often consider the matter 

 of cost and select the cheapest source of protein without 

 in any way impairing the ration. 



