No. fi. DEPARTMENT OF AGRICULTURE]. »! 



MODERN DAIRY SCIENCE AND PRACTICE. 



By L. L. Van Slyke, Ph.D., Geneva, TV. )'. 



INTRODUCTION. 



Daiijing has for its objects the production of milk and the manu- 

 facture of various food products from milk. Dairying may, there- 

 fore, be divided into two fairly distinct departments: Dairying (1) 

 as a branch of agriculture, and (2) as a manufacturing industry. 



Considered as the source of milk production, dairying is a branch 

 of agriculture; for the producer of milk tills the soil, raises food 

 crops for the cattle, rears dairy animals, and obtains milk as his fin- 

 ished product. He is a manufacturer, employing agricultural meth- 

 ods. Considered as a source of cream, butter, cheese, etc., dairying 

 is a manufacturing industry. The maker of butter and cheese starts 

 with milk as his raw material and employs methods that are es- 

 sentially industrial and in no way connected with agriculture proper. 

 While these two departments of dairying have in the past been 

 carried on largely side by side on the farm, the modern tendency 

 has been toward a more complete separation. Attention is here 

 called to these two divisions of dairying, because it is the writer's 

 purpose in this treatise to dwell almost entirely upon the second 

 division. To attempt to cover the field of dairying in its broadest 

 sense would practical!}' involve consideration of a large portion of 

 the broad domain of agriculture. 



Dairying is both an art and a science, whether considered in its 

 restricted or broad sense. 



The art or practice of dairying embraces certain practices and 

 processes which have been gradually developed by experience and 

 observation. The art of dairying, in its widest application, teaches 

 how to cultivate the soil for the production of certain crops; how 

 to make and use fertilizers; how to breed, feed and care for dairy 

 animals for the production of milk; how to produce cream, butter, 

 cheese, etc., from milk. 



The science of dairying embraces a collection of the general prin- 

 ciples or leading truths, arranged in systematic order, relating to the 

 operations of dairying. Thus, among other things, the science of 

 dairying explains the growth of animals, the relation of foods to 

 milk production, the chemical composition and physical properties 

 of milk and its products. It consists of an application of the truths 

 of such sciences as physiology, chemistry, physics, botany, etc., to 

 the practical operations of dairying. 



