8o VARIATION 



butter fat (or butter) produced by Nora, Rose produced 180.7 

 pounds. For purposes of milk production, therefore, feed was 

 worth 39.5 per cent more when fed to Rose than when fed to 

 Nora, and for butter production it was worth 80 per cent more. 

 This, then, is the true measure of the functional difference 

 between these two cows, and it is good and sufficient ground 

 on which to base breeding operations. Further, it is to be noted 

 that this is not the difference between a good cow and a poor 

 one but between two good cows; for Nora produced 348.4 pounds 

 of butter, which, as Professor Fraser remarks, is nearly three 

 times the average yield (130 pounds) of cows in the United 

 States, and almost one half more than the average yield (250 

 pounds) of what are considered profitable cows in Illinois. 



It may be added at this writing (1906) that Rose, though used 

 in many experiments and exhibited at various state fairs and 

 at the St. Louis Exposition, is still living, hale and hearty at 

 sixteen years of age, and is still an economical producer of milk. 

 She has an average yearly record of 384 pounds of butter fat 

 for ten years, 1 and though she has been in many tests since the 

 one just reported she has never been beaten but once. That 

 was in the following case, which bears further on the present 

 point. Three cows were in this test with Rose, Tina Clay's 

 Queen, known to be a poor cow, and two natives, known as 

 No. i and No. 3, supposed to be two of the four best cows bought 

 for experimental purposes out of a herd of one hundred. Reduced 

 to the same feed basis, and taking the yield of Queen as 100, 

 that of No. 3 would be represented by 121, of Rose by 304, and 

 of No. i by 3 12. This is a rate of more than three to one against 

 the poor cow, or over two and one-half to one between good cows 

 on the same feed basis. 



This difference in the efficiency of individual cows is depend- 

 ent not so much upon daily differences as upon the ability for 

 long-time performance. Some cows will give a heavy yield for 

 three or four months, and go dry in six or seven months ; others 

 will give a profitable yield almost continuously. Both extremes 

 are deceptive. The herdsman will almost certainly overrate the 



1 Since the above was written Rose has completed a twelve-year record of 7258 

 pounds of milk and 360 pounds of butter fat as an average. 



