NINTH ANNUAL YEAR BOOK— PART XII 703 
pine. A good silo may be made of redwood in the lower part and of some 
cheaper wood in the upper part where the strain is not so great. 
A successful silo must have a solid foundation sunk below freezing line, 
a smooth perpendicular wall, and the walls must be air tight. Most silos 
are located outside the barn and this is to be recommended, since they 
add much to the appearance of the place and are handier to fill. The size 
will depend upon the number of cattle to be kept. The diameter should 
be such that a layer of at least one and one-half inches will be taken off 
the top daily in feeding to insure fresh silage as it spoils if left exposed 
to the air more than twenty-four hours. A cow will eat one cubic foot, 
or about forty pounds per day. At this rate to feed cattle six months 
the diameter of a 30-foot silo should be such as to allow about five square 
feet of surface for each cow. 
The diameter should vary as the number of cows and the depth as 
the length of the feeding period. Capacity varies as the square of the 
diameter and the wall surface varies directly as the diameter, therefore 
the first cost, as compared to capacity, is less in a silo of greater diam- 
eter. However two small silos are recommended rather than one large 
one because the silage will always be in better condition. 
The use of silos has three great advantages over dry feed methods. 
It is more economical, the feeding value of the product is improved, and 
silos make cattle feeding profitable, hence help to maintain soil fertility. 
The economy of silage results from the fact that cattle wall readily eat the 
entire stalk in silage form, while in whole or shredded dry fodder a 
goodly portion of the stalk is refused. If fodder is stored in a dry shed 
the percentage waste in curing is not much different from the same in 
silos, since there is a portion of silage on top that spoils, but if corn is 
husked in the field the same crop is husked in the field the same crop 
in silage is worth at least 25 per cent more. 
If the crop is to be stored the silo is the most economical storage 
room, since nearly twice the amount of dry matter may be stored in the 
same space in the form of silage than as fodder. Also crops may often 
be siloed that w^ould otherwise be lost. 
The greatest recommendation for a silo is that it increases the feeding 
value of a crop. The increased feeding value does not result from in- 
creased digestability, or from changed chemical composition, but chiefly 
from the physical effect and increased palatability of the silage, therefore 
animals may be induced to eat larger amounts. Owing to its succulence 
silage, like grass, keeps the bowels regulated and tends to maintain 
that degree of healthful vigor so essential in hard worked dairy and 
breeding animals. 
Some silo advantages are indirect. The most laudable thing about the 
silo harvest system is that it does away with selling crops off the land, 
thereby depleting soil fertility. It makes possible a system of stock 
farming whereby nearly all the fertilizing constituents are thrown back on 
the soil in the form of manure. 
Chief among silage crops is corn. If a large amount of coarse feed 
is wanted it pays to plant some large-stalk southern variety, but if a 
richer feed is wanted, northern varieties, which yield more grain, should 
be used. In either case a variety should be selected that will mature 
