THE ECONOMIC FACTORS 



131 



From the source already noted,* figures were compiled 

 showing the increased cost of all the various staple grains 

 which are used for cattle feeding, and also the increased 

 cost of hay. These two sets of figures were combined, giving 



FIG. 18. RELATIVE RETAIL PRICES, 1890-1915 

 M ilk and Bacon 



the two varieties of feeding stuffs (grain and hay), the im- 

 portance which they would play in the feeding of an average 

 dairy cow. From this combination of figures was plotted a 

 curve called the "feed curve." A separate curve was plotted 



* Bulls. 94, 99, U. S. Dept. of Commerce and Labor. 



