HAY AND GREEN FEED 59 



usually cylindrical structure or building. In this is placed 

 the forage usually as it comes from a cutting machine. 

 The material is packed tight by tramping in order to 

 exclude as much air as possible. If necessary, water is 

 added to facilitate the packing. If properly prepared the 

 silage or ensilage will keep for many months. The material 

 is canned on a gigantic scale though it has not been steril- 

 ized. More or less fermentation takes place but not of a 

 character to interfere with its feeding value, nor with its 

 palatability for stock that has become accustomed to the 

 the characteristic taste of silage. If the packing of the 

 silo has been done carelessly the material rots and is 

 worthless. 



The silo is built tall and narrow in order to give greater 

 pressure, thus packing the silage more closely. Further- 

 more, the smaller surface exposed at the top gives less 

 opportunity for spoiling. The top layer exposed to the 

 air rots and must be discarded, unless the feeding is com- 

 menced as soon as the silo is filled. The top layer may be 

 of chaff or other material of little value. If there is a leak 

 in the silo the silage will spoil at this point. The silo may 

 be made of cement, brick or any other building material, 

 but because of the lower cost is usually made of wood. It 

 should be at least 24 feet high to give the necessary pres- 

 sure and bulk. 



The silage should be fed rapidly enough to prevent the 

 exposed upper layer from having time to spoil. For this 

 reason it is not expedient to feed less than ten cows. It is 

 essential to pack the silage tightly as it is placed in the 

 silo. This forces out most of the air. The fermentation 

 uses up the small amount of air remaining and if there are 

 no leaks the fermentation ceases. 



Any kind of forage may be preserved in a silo, but the 



