28 BULLETIN 501, U. S. DEPARTMENT OF AGRICULTURE. 
more productive than those housed in adequate quarters for which 
they are able to pay a reasonable rental charge. On the other hand, 
it is not uncommon to find cows so poorly housed that it is not pos- 
sible for them to make a profitable yield. The location of the farm 
with reference to markets, the degree of cleanhness desired, as well 
as the size and economic productivity of the herd, are factors to be 
considered in relation to an economic investment in buildings. Build- 
ings which would be desirable and economical on a dairy farm near 
the city, where certified milk finds a ready market, would hardly be 
adapted to the use of a herd of the same size where the only market 
is a local cheese factory or creamery buying on the butter-fat basis. 
Neither would a herd having an average production per cow of 4,000 
pounds of milk justify the same investment in buildings and equip- 
ment as one having an average of more than 6,000 pounds per covv. 
The investment per cow in dairy buildings on the four farms dis- 
cussed in previous pages is moderate, being $84 on the Wisconsin 
farm, $50 on the Michigan, $83 on the Pennsylvania, and $80 on the 
North Carolina farm. A larger herd is one reason for the lower 
investment per cow on the Michigan farm. Other things being equal, 
the larger the herd that can be accommodated with a given invest- 
ment the lower the amount per cow. 
The question of an economic investment in equipment and sup- 
plies is closely related to that of buildings, and the same general 
principles hold true in both cases. Expensive milk coolers and ice 
supplies, which may be absolutely necessary in the production of 
high-grade milk for a special market, might be both unnecessary and 
extravagant in the production of cream to be sold on the butter-fat 
basis. In other words, expenses for buildings, equipment, and sup- 
plies should never be so high as to make it difficult or impossible to 
realize a reasonable dividend on the capital invested in the herd. 
The other items in the total cost of milk, including interest, ex- 
pense for use of bull, miscellaneous items, and overhead, depend 
quite largely upon the efficiency of the management of the dairy 
herd and farm business. The charge of interest on money invested 
in cows is in direct proportion to the value of the cows. 
The charge per cow for use of bull is largely in proportion to the 
value of the bull and the number of cows in the herd. In attempting 
to raise the general productivity of the herd through the selection 
and raising of heifers from the best cows, the influence of the quality 
of the bull in the herd is felt for years, and, within reasonable limits, 
any additional cost because of his quality will be far more than offset 
by the increased value of the heifer calves. Furthermore, there is a 
good market for calves of good breeding, and those not needed in the 
herd can be sold for much better prices than those sired by a scrub 
bull. 
