192 HOW TO MAKE SILAGE. 



trate to a depth of tjiree to five feet and in poorly paclced silage 

 will often spoil silage to this depth. 



Experiments with Acid Bacilli in Silos. 



A recent report from the International Agricultural Institute 

 has reference to experiments carried out in Italy by Sigs. Sama- 

 rani and Gorini regarding the introduction of a, culture of lactic 

 acid bacilli during the filling of tlie silo. This is to encourage the 

 presence of this agreeable acid and useful bacillus, and to discour- 

 age the presence of butyric acid and the fermentation Oif molds. 



Sig. Gorini after ten years' investigation distinguishes four 

 types of silage: 



(1) Silage in which butyric acid bacteria predominate. 



(2) Silage in which lactic acid bacteria predominate. 



(3) Silage in which putrefying bacteria predominate. 



(4) Silage comparatively free from bacteria. 



The last two types he considers abnormal — too low a tempera- 

 ture favors the development of putrefying bacteria and too high 

 a temperature destroys all bacterial life; consequently, the making 

 of successful silage depends chiefly on the amount of heat pro- 

 duced in the silo which may be controlled by the packing, and 

 only to a lesser extent upon the moisture content and quality of 

 the forage. The best temperature for the silo is 122°F., at which 

 temperature lactic 'acid bacteria predominate; if the temperature 

 rises to 140°F. the butyric acid flora is especially favored. 



Sig. Samarani's experiments covering many years show that 

 during the first few days after the grass (evidently the crop he 

 used) has been put in the silo, two typical and different fermenta- 

 tion processes take place — an acetic fermentation and a lactic 

 fermentation. 



The first is an intracellular process through which the sugars 

 are transformed, as a result of the heat and almost complete ab- 

 sence of the oxygen, into alcohol and carbonic acid. Later the 

 alcohol is transformed into acetic acid. The second process is an 

 ordinary lactic acid fermentation. Of the total free acid content 

 of normal acid silage, on an average 70 per cent, is acetic acid, and 

 about 20 per cent, lactic acid, but these proportions are later Just 

 reversed in well packed silage. Acetic fermentation can only 

 transform the sugar into acid indirectly, while lactic fermentation 



