112 ILLINOIS STATE DAIRYMEN'S ASSOCIATION. 



one of the cheapest forms is finely ground rock phosphate. For 

 quick returns treated rock or steamed bone meal is the best to 

 use, for the phosphate in the raw rock does not become avail- 

 able to plants until it becomes associated with decomposing or- 

 ganic matter. It is a good plan to mix 40 or 50 pounds of raw 

 rock phosphate to each load of manure before applying it to 

 the land. 



Potassium is found in abundance in the soils of Illinois, 

 and does not need much consideration at present, except for 

 peaty lands. I shall therefore not dwell upon this element but 

 shall consider it when discussing the elements of fertility re- 

 moved in the production of milk. 



In the making of milk the soil is required to give up some 

 of its feritlity. The crops grown for our live stock take from 

 the soil some of the elements which are necessary for the mak- 

 ing of milk. Through the work of investigators it has become 

 possible to determine quite accurately just how much fertility 

 is required to produce a definite amount of milk. The chemist 

 has analyzed the different feed stuffs and found that they are 

 made up of different amounts of elements which have come 

 from the soil and air. Milk has been analyzed and found to 

 contain some of the elements that are found in the soil. In 

 order to present a concrete example, it becomes necessary to 

 assume the amount of feed a good cow will consume in a year 

 and the amount of milk she will produce. No dairyman should 

 be satisfied to keep a cow unless she produces 7,000 or 8,000 

 pounds of milk throughout the year, testing at least 3.8 per 

 cent. A ration consisting of 30 pounds silage, 10 pounds clover 

 hay, 5 pounds corn stover, 4 pounds corn chop, 3 pounds bran 

 and 1 pound oil meal will supply ample nutrients for a cow to 

 produce 8,000 pounds of 3.8 per cent milk in a year. 



During the first part of the animal's lactation period, or 

 when she is giving the largest flow of milk, it will require more 

 grain than I have allowed for this period, but during the resting 

 period, which will be from 6 to 8 weeks, she will not require 

 very much, if any, grain if she has all the silage and clover hay 



