SILAGE PRESERVATION 19 



Heat is also lost by convection, which is the carrying 

 away of heat by the circulation of air from the surface. 



The best kind of house would be uncomfortably cold 

 in the winter if it had no roof or if the doors were left open; 

 it is just as true of the silo. If the doors are open or the chute 

 poorly constructed, much cold air comes in and warm air 

 escapes. This is particularly true of a poor roof or no roof 

 at all. These two losses of heat combine at the surface near 

 the wall to make the freezing most serious at this point. 

 Also, it happens that this point is farthest away from the 

 main body of the silage. Therefore heat reaches it more 

 slowly, and the result is more serious freezing at that point 

 than elsewhere. 



Prevention. Generally, a few inches below the surface 

 there is little, if any, frozen silage near the wall. In view 

 of these facts, two-thirds of the freezing of silage can be pre- 

 vented by simply keeping the outer eighteen inches of the 

 surface of the silage beveled down toward the wall. Thus 

 the silage most likely to freeze is removed before it has time 

 to freeze. During warm or moderate weather the silage 

 surface should always be kept level, but when the silage 

 begins to freeze, the surface should always be beveled near 

 the wall. Absolutely no silage should be allowed to cling to 

 the wall of any silo. 



The roof should always be made tight, and the following 

 pages will show how every roof can be made so. Also, the 

 doors should be kept closed when practicable. If that is 

 impossible, it is doubly important that the chute be well built 

 and kept closed. 



The loss of heat from the surface, due to allowing the 

 silage to stick to the walls, is much greater than the loss of 

 heat out through the walls themselves. So the difference 

 in materials of which the wall is made is of very much less 



