SWEET ENSILAGE. .261 



a long time without dread of spontaneous ignition. Hence this 

 method is frequently employed in rainy districts, e.g. the North 

 Sea littoral and the Austrian Alps. It is, however, inadvisable to 

 resort to this practice where good air-dried hay can be made from 

 the green fodder at disposal, because the feeding experiments 

 performed by G. Kiihn and others, and reported by FR. ALBERT 

 (I.) and FR. FALKE (I.), concordantly demonstrate that the pre- 

 paration of brown hay is attended with a considerable loss 

 (amounting to as much as 50 per cent, of the total) of digestible 

 protein substances. 



155. Sweet Ensilage. 



The preparation of brown hay is also partly dependent on the 

 weather, in so far that a certain amount of dryness in the material 

 before stacking is essential. Now, in many cases, it is either 

 practically impossible or economically disadvantageous to remove 

 from the green fodder even the small quantity of water that must 

 be got rid of in making brown hay. One instance of this kind is 

 afforded by the enormous quantities of beet leaves available for a 

 few days only in each year (during the ingathering of the beet 

 crop), and another is the drying of the de-sugared slices of beet, 

 an operation impracticable in many places owing to the lack of 

 the necessary costly drying apparatus. In such, and many other 

 similar cases, putrefaction of the readily decomposable masses is 

 prevented by subjecting them to an acid fermentation without any 

 previous drying. Formerly this was effected exclusively in silos 

 whence the term ensilage, current for this operation in England 

 and France, is derived. 



According to the composition of the raw materials, their water- 

 content and method of treatment, two classes of durable fodder 

 are obtained, viz., green pressed fodder and sour fodder. The 

 main factor determining which of them shall be produced is the 

 height of the temperature attained, as the result of spontaneous 

 heating, in the mass. If this does not exceed 40 C., then the 

 butyric ferments develop along with the lactic acid bacteria, 

 and a sour-smelling product, known as sour fodder, results. 

 .More detailed particulars of this are given in the next para- 

 graph. 



If, on the other hand, the thermogenic bacteria develop vigo- 

 rously in the heap, and thus cause the temperature to rise rapidly 

 to 50 C. and remain there for some time, then the lactic acid 

 bacteria develop by preference, overcome all their competitors, 

 and exert a practically undivided sway. In this case a durable 

 fodder is obtained, which is almost entirely free from volatile 

 acids and devoid of odour, or with a somewhat sweetish smell, on 

 which account it is known as sweet fodder ; though this name is 

 hardly correct, owing to the strongly lactic acid character of the 



