STATE DAIRY ASSOCIATION. 275 



the cream from becoming dry or hard on the sides of the bottle. The 

 jars that were used for keeping the composite samples were one-half 

 pint, tin top, covered bottles. When the period of weighing and sam- 

 pling was completed, the samples were tested either on the farm or at the 

 creamery. 



CALCULATING THE AMOUNT OF MILK AND BUTTER FAT. 



The milk was weighed and sampled during the fourth week of the 

 seven-weeks period. From the total amount of milk that each cow gave 

 during this time, and the per cent of fat, was calculated the amount of 

 butter fat produced in the week. From these results were estimated the 

 amount of milk and butter fat each cow produced during the three 

 weeks before, and the three weeks following the test. The cow's yearly 

 record was made up from these tests, and in this way the total amount 

 of milk and butter fat that she produced during the entire year was 

 determined. It may be objected to that this method did not secure re- 

 sults absolutely correct. On this it may be said that the chief object 

 was to secure data from which cows could be compared with each other, 

 and that this object was fully attained even though the totals may have 

 been either slightly too large or too small. Check methods show, how- 

 ever, that the data are very close to the actual amounts produced. In 

 many cases the dairymen also kept an approximate account of the grain 

 and roughage that each cow consumed during the year. Where this 

 was done the records are of exceptionally high value, for they clearly 

 show the profit or loss of every cow kept in the dairy. 



Ten dairy herds, namely A, B, C, E, F, I, J, L, M and N, have 

 been tested for two years and I will give you the summary of the ten 

 herds and a detailed report of two dairies. In the ten herds 145 cows 

 completed their second year's work. The best cow gave an average 

 yield of 7,190 pounds of milk, 367 pounds of butter fat, and 428 pounds 

 of butter. The poorest matured cow gave an average yield of 4,560 

 pounds of milk, 135 pounds of butter fat and 158 pounds of butter. 



In the first two years the average production of the herds was: 

 4,944 pounds of milk, 201 pounds of butter fat, and 235 pounds of butter. 



The average production for the two years was : 5,261 pounds of milk, 

 214 pounds of butter fat and 249 pounds of butter. 



Herd "A" made the greatest increase in the second year's test. It 

 produced 1,285 pounds more milk and 60 pounds more butter fat per 

 cow than it did in the first year's work. The percentage of increase 

 was: 32.4 per cent of milk and 42.5 per cent of butter fat. 



In herd "B" there was a small decrease in the second year's test, 



