COMMON PRACTICE OF FEEDING 141 



There are a few fundamental principles that are neces- 

 sary to get good results from any system of swine feeding. 

 One is that the pig must have a certain amount of pro- 

 tein, more than is found in corn. In other words, he must 

 have a more nearly balanced ration than corn can sup- 

 ply. Secondly, he should have a variety of feeds because 

 the greater the number of feeds in a ration the better will 

 be' the results obtained from its use. When skim milk 

 was used in the American experiments in addition to 

 corn, it furnished the protein and also improved the ra- 

 tion very greatly by way of variety. Corn is a carbona- 

 ceous concentrate and skim milk in limited quantities is a 

 nitrogenous concentrate. Thus by the addition of skim 

 milk to this otherwise corn ration, very much better re- 

 sults are possible which would naturally be accredited 

 to the milk. Aside from this, by comparing corn with 

 corn and skim milk, the latter ration is doubte in effi- 

 ciency so far as variety is concerned. 



In the Danish experiments where several small grains 

 were used, neither one of these differences is so great. 

 The small grains, such as barley and rye, contain more 

 protein than corn ; hence the addition of the protein in the 

 skim milk was not so effective. Where several small 

 grains are used in the basal ration, the addition of skim 

 milk does not improve the ration so greatly by way of 

 variety. Consequently it is easily seen how results like 

 these must be properly interpreted before they can be 

 used to the best advantage. 



American experiments also show that cow-peas are 

 equal in food value to corn. Cow-peas are a nitrogenous 

 concentrate and corn is a carbonaceous concentrate. 

 Neither one of these two feeds used separately produces 

 a well balanced ration. In the one cage there is too much 



