Equipment 379 
feed to last five months, or 150 days, this would necessi- 
tate the storage of 1050 pounds of feed for each sow. 
If pigs are also to be fattened from the same supply, 
about 700 or 800 pounds should be allowed for each pig. 
A safe average would be about 124 cubic feet of bin room 
for each farrowing pen, or if the herd is to be fed from the 
central house the entire year, double this amount. The 
mixing floor should be five or six feet each way and should 
preferably open into the alley so that there will be room 
for manipulating the shovel handle without needing to 
leave special space for this. 
If a large quantity of ground grain is mixed and stored 
for a considerable period of time, there is danger of it 
spoiling, so that in case a large plant is being installed, 
it is safer to have the grinder in the same building with 
the feed, and only grind small portions of feed at a time. 
In most cases, however, if the feed is stored very dry and 
the building is watertight, there will be but little difficulty 
from having grain spoil, and the plant on the average 
farm will not usually be large enough to justify the in- 
stallation of a grinder and power plant solely to grind 
hog-feed. 
The power is the greatest expense and when the farm 
already has an engine or other power, the grinder will cost 
very little. A good burr grinder suitable for general farm 
use will cost from $25.00 to $50.00 and will take five to ten 
-horse power. A roller grinder will cost $100.00 to $150.00, 
but there are-no burrs to wear out so that when any large 
quantities of grain are to be ground, the final cost of 
grinding a bushel of grain will be less than with the burr 
mills. The roller mill, if used, must have corrugated 
rollers and be equipped with a differential so as to grind 
as well as roll. Pigs require that the grain be ground 
