CHAPTER II. 



HOW TO BUILD A SILO. 



Before taking up for consideration the more important type 

 of silo construction, it will be well to explain briefly a few funda- 

 mental principles in regard to the building of silos which are com- 

 mon to all types of silo structures. When the farmer understands 

 these principles thoroughly, he will be able to avoid serious mis- 

 takes in building his silo and will be less bound by specific direc- 

 tions, that may not always exactly suit his conditions, than would 

 otherwise be the case. What is stated in the following in a few 

 words is in many cases the result of dearly-bought experiences 

 of pioneers in siloing; many points may seem self-evident now, 

 which were not understood or appreciated until mistakes had 

 been made and a full knowledge had been accumulated as to the 

 conditions under which perfect silage can be secured. 



General Requirements for Silo Structures. 



1. The silo must be air-tight. We have seen that the process 

 of silage making is largely a series of fermentation processes. 

 Bacteria (small plants or germs, which are found practically 

 everywhere) pass into the silo with the corn or the siloed fodder, 

 and, after a short time, begin to grow and multiply in it, favored 

 by the presence of air and an abundance of feed materials in the 

 fodder. The more air at the disposal of the bacteria, the further 

 the fermentation process will progress. If a supply of air is ad- 

 mitted to the silo from the outside, the bacteria will have a chance 

 to continue to grow, and more fodder will therefore be wasted. 

 If a large amount of air be admitted, as is usually the case with 

 the top layer of silage, the fermentation process will be more far- 

 reaching than is usually the case in the lower layers of the silo. 

 Putrefactive bacteria will then continue the work of the acid 

 bacteria, and the result will be rotten silage. If no further sup- 

 ply of air is at hand, except* what remains in the interstices be- 

 tween the siloed, fodder, the bacteria will gradually die out, or 

 only such forms will survive as are able to grow in the absence 

 of air. 



Another view of the cause of the changes occurring in siloed 



21 



