24 



emptying the silage, it is not handy to bring it up from 

 such depths. 



To build a structure above ground to a convenient height 

 is the natural way out of the difficulty. To-day we find 

 thousands of such buildings in use throughout Canada and 

 the United States, and as we have said they are now being 

 introduced into Australia. 



They are generally built of wood, stone, brick or of com- 

 binations of these. 



One factor, which is apt to be overlooked or under- 

 estimated, in the erecting of those silos is the surprising 

 amount of outward pressure which occurs when the silo, 

 especially if it is a high one, is full. 



An ordinary built shed or old stable or mill will not as 

 a rule bear conversion into a silo, as the walls are almost 

 certain to bulge out, and either collapse altogether or be- 

 come worthless for the purpose of an airtight structure. 

 Square or rectangular buildings are much less liable to with- 

 stand this strain than circular ones having walls of the 

 same thickness. Circular block-house-like buildings have, 

 therefore, generally superseded those of other shapes. The 

 site to choose is of great importance. In the case of a 

 dairy farm where the cattle are fed in byres, this kind of 

 silo should be as near as possible, in fact, it might with 

 advantage form part of the same building. 



As to the size of the silo, depth and diameter, these will 

 naturally depend on the quantity of silage which it is re- 

 quired to make. From the table below and our previous 

 remark? on quantities generally fed per animal, the height 

 and diameter may be reckoned. 



A point which here demands attention is this. In the 

 emptying of a silo 20 feet deep, of, say, a diameter of 25 

 feet to feed 18 cows, one requires 720 Ibs. silage per day, 

 allowing 40 ibs. per head. Suppose we are just opening it. 

 We require 40 cubic feet, reckoning 18 Ibs. to a cubic foot. 

 It is better to empty by taking off layers horizontally with 

 a fork without making holes here and there. Forty cubic 

 feet equals 00,120 cubic inches ; the area of the surface 

 of the silage would in this case be 70,560 sq. inches. That 

 would mean that for the first few days silage would 

 be removed to the depth of approximately one inch, at 

 which rate moulding would very likely set in. So 

 that it would be advisable to decrease the horizontal 

 feeding area by having the inside diameter 23 feet instead 



