70 ILLINOIS STATE DAIRYMEN'S ASSOCIATION 



We do not know what the application may become in 

 dairy cows. Perhaps some time or other we may find men 

 specializing on milk for babies in large cities, who will 

 have bakeries or ultra-violet lamps in the dairy barns, to 

 shine on the back of each cow a certain number of min- 

 utes. Then they can turn out a milk guaranteed to cure 

 ricketts, and there are plenty of people in the cities who 

 have rickitic children, who would be willing to pay a long 

 price for milk of that kind, because it will be produced at 

 a greater cost than the highest grade of certified milk. We 

 do not know what the practical application will be, but 

 it is of profound significance. 



This ultra-violet lamp has a milky arc like these milky 

 lights you have seen in printing plants. This sketch shows 

 bluish lights, except that those lamps are housed in glass 

 containers, and they are not ultra-violet because glass will 

 not permit any of the ultra-violet rays to pass through, 

 while these lamps are enclosed in quartz glass which is 

 very expensive, because it is hard to make, and that quartz 

 has the property of permitting the ultra-violet light to shine 

 through. A person cannot look at this ultra-violet light 

 without wearing glass goggles, without severely injuring 

 the eyes. So far, then, with reference to that. 



I am going to just conclude, and if you have some 

 questions with reference to this, I will be glad to answer 

 them. 



In summarizing our recommendations with reference 

 to minerals for dairy cows, they are simply the statements 

 I made this morning. The best way I know of supplying 

 the material the dairy cow needs is to provide an abund- 

 ance of good legume hay throughout the winter season, and 

 I would add, furnishing plenty of good green feed, espe- 

 cially pasturage through the growing season. 



If the dairyman does not have an abundance of le- 

 gume hay for his dairy cows, then by all means in the win- 

 ter time feed a mineral supplement, supplying lime. I 

 mentioned this morning that the protein-rich feeds are in 

 general high in phosphorus, so that if one-fifth or twenty 

 per cent of the concentrate or grain mixture is made up of 



