212 ILLINOIS STATE DAIRYMEN'S ASSOCIATION. 



cows differ from each other. in the amount of this vari- 

 ation. Compare plates 2 and 3. 



Cow No. 2. A very nervous and somewhat vicious 

 animal goes to great extremes, while cow No 5, a mild- 

 eyed " mooly cow, " produces milk comparatively uni- 

 form in quantity and quality from day to day. 



Third: The mixed milk of several cows is more uni- 

 form in amount and richness from one day to another 

 than the milk of one cow. 



The record of each milking of cow No. 2, plate 1, 

 shows the general tendency to equalize the milk pro- 

 duction by going to both extremes. May 19, she gave 

 12.75 lb. milk in the morning, and 7 lb. at night. The 

 morning milk contained 6.5 per cent, of butter fat, the 

 night milk only 2 per cent. The average per milking 

 of this cow for three months has been 9.35 lb. milk and 

 3.92 per cent, of fat. In general it can be seen that in 

 this record when one milking was above the average in 

 quantity and quality, the next milking went below, 

 and vice versa. 



During the 66 days represented in plate 2, the daily 

 quantity of milk from both milkings varied from 23 

 to 17 lb.; the per cent, of butter fat in the daily milk 

 from 3 to 6.1, and the pounds of butter fat in the daily 

 milk from 0.56 to 1.29. 



The daily record of cow No. 5 for the 66 days shows 

 a very uniform per cent, of butter fat, varying only 

 from 2.8 to 3.4. The same regularity is seen in the 

 total daily production of butter fat, 0.65 to 0:42 lb.; 

 and plate 3 shows that the course of the line represent- 

 ing the pounds of butter fat gradually declines from 

 May 1st to July 5th. A decrease in the pounds of 

 milk from day to day is also shown in the record of 

 this cow. 



