202 ECONOMIC PLANTS 



The silo must have smooth, vertical walls which will 

 offer no resistance to the uniform settling of the fodder. 

 Otherwise air spaces may be formed, and thus the fodder 

 be spoiled. 



The walls of the silo must be very strong so as not to 

 give way as the mass settles. The outward pressure 

 of cut fodder corn is great and the walls of rectangular 

 silos especially are apt to spring. In the round wooden 

 silos every board acts as a hoop, and as boards stretch 

 but little lengthwise, there is little spreading in these 

 silos. Stave silos secured by iron hoops have proved 

 satisfactory in resisting pressure from settling and are 

 used very extensively. Very satisfactory silos are also 

 built of brick, of hollow tile, of cement blocks. Probably 

 the most satisfactory silo is the cylindrical reenforced 

 cement silo. It has all the advantages of the best 

 wooden silos and in addition it is practically ever- 

 lasting. 



The size of the silo must, of course, be determined 

 by the size of the herd to be fed from it. It has been 

 determined by experiment that about 40 pounds daily 

 is a good average food ration for cattle a head. If the 

 season for feeding is 180 days, this will mean 7200 

 pounds for each cow. As silage loses about 10 per 

 cent in weight by fermentation, there must be put into 

 the silo about 8000 pounds, or 4 tons, for each animal. 

 One ton of silage occupies about 50 cubic feet, therefore 

 the fodder for one animal will require a space of 200 

 cubic feet, approximately. 



The following table shows the capacity in tons of 

 circular silos from 20 feet to 36 feet in depth, and 

 lofeet to 18 feet in diameter, also the number of acres 

 of corn, averaging 10 tons to the acre, necessary to fill 



