Cost of Milk Production. 77 



ing discussions we have based our figures upon the actual fat produced 

 by the cow as determined by the Babcock Test and not upon the 

 amount of .butter that such fat might be expected to make. We have 

 done this because we believe it to more accurately measure the pro- 

 ducing powers of the different cows. But since butter has to many a 

 more significance than fat, we have made the following calculations: 



The average yield of fat per cow was 285.62 lbs. If all this fat had 

 been made into butter that contained 80 per cent of fat * we should 

 have had a butter yield of 357 lbs. per cow. The best cow gave 

 439.37 lbs. of fat. On the same basis this would be equivalent to 549 

 pounds of butter. 



But not all the fat can be made into butter, some is unavoidably lost 

 in the skim-milk and in the butter-milk. Assuming that four-fifths of 

 all the milk would be skim-milk and that it would contain .25 of one 

 per cent of fat and that three-fourths of the cream would be butter- 

 milk and it should contain .5 of one per cent of fat, we should lose in 

 this way 398.23 lbs. of fat or 19.91 lbs. per cow, equivalent to 24.9 

 pounds of butter. This subtracted from 357 would leave the average 

 yield of butter per cow 332 pounds after making due allowance for the 

 losses in skim milk and butter-milk. 



The cows in general are fresh in the months of September and 

 October of each year. In table No. V are shown the dates at which 

 calves were dropped both before and during the experiment and also 

 the number of days that each cow was actually milked from January 

 15, 1891, to January 14, 1893. It will be seen that one cow, May, was 

 farrow at the time of the beginning of the experiment, that two others, 

 Carrie and Jennie, went farrow during the experiment, and that Shadow 

 and Sue were not bred. The general plan of treatment of the Univer- 

 sity herd is that the cows shall be milked ten months in the year, going 

 dry about eight weeks before calving. On referring to the last column 

 of table V it will be seen that this is very nearly practically carried 

 out, and that the average number of days of milking was 304; almost 

 exactly ten months. 



* This is the standard adopted by the judges of the Dairy Test at the World's 

 Columbiau Exposition. 



