12 THE STORY OF MILK 



of pounds by ten and adding the totals for the year. 

 Occasionally the milk may be subjected to tHe Babcock 

 Test to ascertain its richness ; three or four times during 

 the period of lactation is sufficient. 



Where farmers do not have time to do the test- 

 ing themselves they often combine and hire a young 

 man or woman, trained in an agricultural college, to 

 go around from farm to farm and do the work. These 

 experts not only test the yield and the percentage of 

 fat but also weigh and compute the feed so as to help 

 the farmer make up his rations and calculate whether 

 each cow pays for her feed or not. The members of 

 these associations meet and compare notes and a 

 friendly rivalry is stimulated which may do much 

 toward increasing production. As a matter of fact, 

 where Cow Test Associations have been introduced, 

 both yield and quality of the milk have been largely 

 increased. 



Healthy Cows alone can be depended upon to pro- 

 duce sanitary milk. In many herds of milk-cows tuber- 

 culosis is prevalent, and constant vigilance is necessary 

 to prevent its spread. The Tuberculin Test discovered 

 by Koch is invaluable for the purpose of ascertaining 

 the presence of tuberculosis. It is not necessary, how- 

 ever, to kill every infected animal. Only where the 

 lungs or the udder is affected and a physical exam- 

 ination shows an advanced stage of the disease such 

 radical means are advisable. When the tuberculin test 

 was first introduced many valuable herds were wantonly 

 and foolishly killed off because some of the highly de- 

 veloped dairy cows showed reaction to the test while 

 worthless scrubs were allowed to live and spread the 

 disease. For only the intelligent and public-spirited 



