8 BULLETIN 1*7*7, U. S. DEPARTMENT OF AGRICULTURE. 
and Pacific States the number of acres per dairy cow is decreasing; 
in other words, dairy farming is becoming more important as an 
agricultural industry. In the West South Central and Mountain 
States, other types of farming increase faster than dairying. 
PRODUCTION OF BUTTER PER COW. 
During the last 40 years the average quantity of butter produced 
per cow has increased 30 pounds. This fact must not be taken as a 
measure of the increase of the productivity of dairy cows, for the 
relative quantity of the total milk production used for cheese, or 
consumed raw, may have varied considerably. In the New England 
and Middle Atlantic States the production of butter, compared with 
the total number of dairy cows, was lower in 1910 than in any census 
year since 1870. This indicates that a larger quantity of the milk 
produced is being used for other purposes. Another interesting fact 
is that in all of the southern and western States the average produc- 
tion per cow is increasing. For cheese, the average production in the 
East North Central States has been increasing, while in the Middle 
Atlantic the tendency is toward a decline. 
The average yields of milk per cow, as obtained from the last three 
censuses, have been obtained by somewhat different methods, so that 
comparison of one census with another can not be made with any 
degree of accuracy. One fact, however, appears in all three — that is, 
the average production in the New England, Middle Atlantic, and 
East North Central is much larger than that of the Southern States. 
It also seems that the production in the Pacific and Mountain States 
is increasing. 
FACTORY PRODUCTION OF BUTTER AND CHEESE. 
Not only have there been marked changes in the yield of butter and 
cheese and milk per cow and per person, but in the last 40 years 
cheese manufacture has changed from a farm operation to a factory 
system. Butter production is rapidly moving in the same direction. 
In 1870, 33 per cent of the total cheese made in the United States was 
produced on farms; and in 1910, only 3 per cent. In 1870 all the 
butter was produced on farms, but in 1910 only a little over 60 per 
cent. It can readily be realized what a change the introduction of 
the factory system has made in the dairy industry. These changes 
have taken place where the dairy industry is most intense. There 
has not been developed to any great extent in the United States a 
method whereby the factory system of making butter and cheese can 
be carried on where the number of cows is small. 
