SILOS AND SI LACK. 74 1 



bottle and makes that bottle airtight, would just realise that when lie puts 

 green material into a silo it naturally cooks itself, so to speak, be could go 

 ahead with greater confidence. 



[f certain simple instructions are followed boldly there is practically no 



danger of failure. 



The General Principles. 



"Ensilage" and "silage" are the terms usually applied to the foodstuff 

 obtained by "ensiling" or storing succulent green fodder in a receptacle 

 or stack in such a manner that it retains its succulence and most of its 

 colour. Tin- jinn-ess of ensiling consists of storing the forage plant under 

 pressure in a silo, stack, or pit, and regulating the resultant heat so as to 

 prevent rotting or decomposition, but yet to allow of a certain amount of 

 fermentation. It is this fermentation which causes the odour which is 

 peculiar to silage. 



The fermentation of plants is mainly due to the action of micro-organisms, 

 and the principle of ensilage is to encourage the action of these micro-organisms 

 up to a certain stage, and when this stage has been reached to check ol- 

 dest roy them. When green plants are heaped together fermentation soon 

 begins, and the temperature increases rapidly. This increase of temperature 

 causes a very great development in bacterial activity, and fermentation 

 proceeds very rapidly until the temperature goes somewhat above 125 deg. 

 Fah. When a temperature of about 140 deg. Fah. is reached many of the 

 organisms that have produced fermentation are destroyed, and hence fermen- 

 tation proceeds more slowly until a temperature of (say) 160 degrees is 

 reached, when all the organisms are destroyed, and spores or seeds only 

 remain alive. Fermentation then stops, and not until the temperature 

 decreases considerably and air gains access to the foddei can asecondary 

 fermentation begin. Thus the food is preserved. 



The organisms that produce acid cease to do so at a high temperature, and 

 the amount of acidity produced will depend on the length of time at which 

 the silage remains at a temperature below (say) 130 deg. Fah. If the 

 fermentation is slow, and the heat develops slowly, more acid will form than 

 if the fermentation is rapid and a high temperature is quickly reached, and 

 generally sour silage will then be produced. 



Sweet silage is obtained by filling the silo slowly, thus allowing sufficient 

 oxygen to remain in the heap to enable the heat-loving organisms to set up 

 a brisk fermentation, form considerable heat, and practically check all 

 fermentation and decay. By adding further fodder more weight is added, 

 thus shutting out fresh oxygen, and checking and controlling the amount of 

 fermentation and heat. Pressure then is the main agent for controlling the 

 temperature, and hence the fermentation. 



If the silo is a good depth, the weight of the fodder is of itself sufficient for 

 the lower half of the silage, but the upper portions, especially the 5 or 6 feet 

 near the top, do not receive sufficient pressure to ensure a proper fermentation 

 and preservation, and as a result this portion may become mouldy, dry, and 

 practically useless. By covering the top of the silo with some such substance 

 as wet chaff, the air is excluded, and the top of the silage, even though 

 impressed, is improved. Still further improvement can be produced, if, in 

 addition to covering to a depth of about 1 foot with damp chaff, some pres- 

 sure is applied, the main thing being that the pressure shall be constant. 

 Any method of pressure which requires daily attention, such as screwing 

 up, cannot be constant, and hence is not so effective. Silage pits have been 



