CATTLE FOODS NATURAL PRODUCTS 231 



large extent unless the conditions in the silo are very 

 bad, so that putrefactive fermentations set in. An exten- 

 sive loss of nitrogen compounds certainly would indicate 

 very serious and long-continued destructive changes. 



Steaming the corn seems to depress the fermenta- 

 tions and decrease the percentage of acids that form. 

 Knisely found .3 to .88 per cent acidity in steamed silage 

 and 1 to 1.6 per cent in unsteamed. 



315. Corn an important silo crop. The nature of 

 the changes and losses in producing silage have been 

 dwelt upon partly because corn, the principal silo crop, 

 is one of our most important forage crops, perhaps the 

 most so on a dairy farm, and partly in order to illustrate 

 the necessity and value of good management in preserv- 

 ing this crop by the silo method. Moreover, the loss that 

 is incident to the field-curing of maize is practically the 

 same in kind and is fully as large as that pertaining to 

 silage, so that the facts presented are pertinent to both 

 methods as well as to all circumstances where similar 

 oxidations and fermentations are likely to ensue. 



316. Extent of loss in the silo. The extent of the loss 

 of dry substance is important. It measures in a general 

 way the difference between the food value of the silage 

 and of the fresh material. The silo combustion reduced 

 the energy or heat value which the fermented fodder 

 will have whenever it is eaten by the animal. The 

 heat lost would supply energy to an animal were the 

 combustion to occur within the animal instead of in the 

 silo. It is desirable, therefore, to know the extent to 

 which dry substance is actually broken up in the prepara- 

 tion of silage. This loss has been measured by several 

 investigators, and, as was to be expected, it has been 

 found to depend greatly upon the conditions involved, 



