4 PREFACE 



form of barnyard manure. The butter and cheese 

 which are sold from the farm contain so small a 

 portion of soil matter that this loss is scarcely 

 perceptible. This is the chief reason why dairy 

 farming is proving so profitable and is coming 

 so rapidly into popular favor. 



Eecent investigation has shown that the dairy 

 cow will convert grain and roughage into human 

 food more economically than can be obtained 

 from any other animal. Under favorable condi- 

 tions 30 per cent of the digestible nutrients 

 fed to a dairy cow are recovered again in the 

 milk, while only about 5 per cent of them are 

 retained in the body of a steer. In other words, 

 a dairy cow makes use of six times as much of 

 the raw material fed as does the steer. This is 

 a most surprising revelation. 



But this is not all. Dairy farming promotes 

 crop rotation and encourages the production of 

 clover, alfalfa, and other leguminous crops which, 

 if fed on the farm, do not wear out the soil, 

 but may positively add to its fertility. The pro- 

 gressive dairy farmer not only finds himself 

 placed, through his industry, in a position of 

 competence and ease, but under wise manage- 

 ment he finds the soil of his farm growing richer 

 and more productive. All of these somewhat 

 surprising assertions admit of absolute proof and 



