
New Yorx Acricunruran Experiment Station. 153 
Changes in the Relative Size of Milk Globules in Successive 
Periods of Lactation. 
In the following table is ziven the size and number per thousand 
a of milk globules in the several breeds of dairy cattle; of four breeds 
- for first, second and third period of lactation, for six breeds for 
the first and second period of lactation and for seven breeds 
i for the first period of lactation. : 
This table includes the actual count and measurement of 
g 42,261 globules, or 536 counts averaging seventy-five globules each, - 
of seven different breeds and of twenty-three different animals. 
_ A careful study of this table will repay one who desires to learn 
_ the characteristic differences of the milk of these breeds, and will 
_ throw much light upon the deportment of the several milks in 
_ the operations of the dairy. — 
___ It will be seen that there is as a general rule, a steady increase 
’ 7 in the number of the smaller globules and a decrease in the larger 
. globules during successive periods of lactation, the average per- 
E . centage changes being given at the bottom of the table, where it 
will be seen that the smaller globules below one on the micrometer — 
scale have increased 68 per cent. in the second period over what 
_ they were in the first; the largest globules (from four to six upon 
| the scale) have decreased during the second period of 67 per cent. 
of their number during the first period; while the intermediate 
- globules during the second period (from one to four upon the scale) 
_ have fallen to eighty-three per cent. of their number during the 
- first period. | 
q A similar change is seen to have taken place when comparing 
a _ the globules of the second period with those of the third period. 
~ It is to be remembered that these changes are similar to in char- 
acter but not the same as those taking place during any one 
_ period of lactation. 
ie 20 
b 
a 









