18 , BULLETIN 128. 



20 head of cattle would consume 72 tons. But it 'should be 

 remembered that it requires a silo of not less than 80-tons' 

 capacity to hold 72 tons of well made silage. A cylindrical silo 

 of this capacity will measure about 14 feet in diameter and 28 

 feet in height. 



A good rule to follow in determining the size of a silo is to 

 estimate the amount of silage that is to be fed during the year 

 and assume a weight of 40 pounds for every cubic foot of silage. 



LOCATION OF SILO. For convenience of feeding, the silo 

 should be as near the manger as possible. It is preferably 

 joined to the barn at one end by means of a chute, so that one 

 can step into the silo without leaving the barn. Where the silo 

 is thus located, it is necessary to prevent the escape of silage 

 odors at milking time, by providing doors for closing up the 

 chute leading to the silo. 



CONSTRUCTION OF SILO. Silos should be round, having the 

 appearance of a cylinder whose height is about twice its dia- 

 meter. They may be built of wood, stone, brick, concrete, or a 

 combination of two or more of these. As a rule, the choice is 

 determined by the relative cost and availability of the materials 

 mentioned. 



In building a silo, four things must be kept in mind. First, 

 it must be air-tight. Second, it must have sufficient strength 

 and rigidity to enable it to withstand the pressure of the silage 

 without yielding. Third, it must have a smooth inside surface 

 to permit the silage to settle readily. And, fourth, it must be 

 deep so that the weight of the silage will give compactness suf- 

 ficient to expel the air which is held between the particles of 

 milage. 



It is desirable that the total depth of the silo be at least 30 

 feet. Where the ground is dry, five or six feet of this depth may 

 be underground. When 30 feet is selected as the fixed depth, 

 the silo can be made of the desired capacity by selecting the 

 proper diameter, which may vary from 12 to 24 feet. 



For want of space we. shall attempt to describe briefly only 

 one type of silo, one which has proven very satisfactory, both 

 in efficiency and in cheapness of construction. This is known 

 as the Curler silo, a detailed description of which is given in 

 Bulletin No. 125 of the Wisconsin Experiment Station. Fig. 

 1 shows a vertical section through this silo. 



