118 DAIRY CATTLE AND MILK PRODUCTION 



full significance of individual variation has been appreciated 

 by those who are engaged in dairy farming. One of the weak- 

 est points in the system of dairy farming as carried on at the 

 present time is the failure on the part of a large number to ap- 

 preciate the importance of this factor of individual selection, 

 or, if it is appreciated, a failure to give this subject the atten- 

 tion and time its importance justifies. Even where cows are 

 milked regularly and the selling of dairy products is a regular 

 business, the yearly butter production seldom exceeds 250 

 pounds per cow except in the hands of the special dairyman. 

 Even among those who are making the sale of dairy products 

 their principal source of income, the average production is 

 comparatively low. 



The Illinois Experiment Station, 1 after testing 18 herds, in- 

 cluding 221 cows through complete milking periods, reported 

 the average milk production to be 5617 pounds and fat pro- 

 duction 227 pounds. The best herd averaged 350 pounds, the 

 poorest 142 pounds of butter fat per cow. The ten best cows 

 averaged 389 pounds, the ten poorest 142 pounds of butter fat 

 per cow for the year. Herds which had been graded up by 

 the use of a pure-bred sire produced 85 pounds of butter fat 

 more per cow than did those in which no grading had been 

 done. These herds were in the hands of men who were 

 making the production of milk their principal business. As a 

 result of this investigation it was concluded that at least one 

 third of the cows in the ordinary herds which were being used 

 for milk production in that state were unprofitable, and that 

 on nearly every dairy farm a few cows were kept at an 

 excellent profit, some at a small profit and some at an actual 

 loss. A summary of these tests is given in Table 1 : 



1 Circular No. 102, 111. Exp. Station. 



