ILLINOIS STATE DAIRYMEN'S ASSOCIATION. 1 39 



Fahr., and, as this temperature destroys those organisms which 

 produce many kinds of fermentation, the only further change 

 which can take place in this silage is a continuation of the 

 oxidation until all oxygen is consumed. Further chemical 

 change will then cease, and the resulting silage will be that 

 which is known as "sweet silage." On the other hand, if by 

 tramping upon the grass and by rapid filling of a silo the 

 greater portion of the oxygen is expelled, oxidation is limited, 

 and the silage never reaches a temperature of 120 Fahr. The 

 organisms of fermentation are then not destroyed, and the 

 changes which they bring about — the formation of acetic acid, 

 butyric acid, and lactic acid — proceed slowly yet surely so long 

 as the silage remains in the stack or silo. The result is sour 

 silage. Side by side with these changes there are others, by 

 which substances valuable as food in the grass are converted 

 into substances having little or no nutritive value. Hence all 

 silage is inferior as a food to the substance from which that 

 silage was made had that substance been consumed while suc- 

 culent. Further, there can be no doubt that the loss is greater 

 when sour silage is made than it is when sweet silage is made. 

 In feeding experiments on milch cows this loss is not at first 

 seen, because sour silage tends, like grains and all substances 

 slightly acid, to promote the secretion of milk. But the real 

 advantage which silage possesses over hay is due to the fact 

 that in the former the cellulose remains mainly in the digestible 

 condition 5 as it exists in grass and other succulent crops, while 

 the water natural to the grass is mostly retained. 



The only conclusion which we can draw from the experience 

 of feeding milch cows with succulent food and silage is, that the 

 water which exists naturally in a vegetable tissue has a special 

 effect upon the animal, and cannot be adequately replaced by 

 water drunk in the usual way. In my opinion, it seems that in 

 vegetable matter there is an intimate union between this water 

 and the chemical constituents of the vegetable. What this 

 union or chemical combination is cannot as yet be said. In 

 mineral substances we know that water can exist in initmate 



