A. Amos and H. E. Woodman 359 



Per lUOgrma. dry oat and tare silage: 



Bags 1 2 3 4 G 7 S 



Unspoilt 

 sample 



Non-volatUe acidity calculated 0-53 7-22 6-11 311 2-51 5-17 2'85 2-48 



as lactic acid, % 

 Ether extract in dry matter, o„ 3-12 3-21 3-37 3-18 3-15 305 2-81 2-70 



It would be anticipated that the amount of ether extract in the 

 silage after drying at 100° would show some correspondence with the 

 amount of non-volatile acidity calculated as lactic acid. This was the 

 case in the material of bags 4, 5 and 7 and in the unspoilt portions of 

 bag 8. Wide discrepancies occur, however, in the figures for the silage 

 in bags 1, 2, 3 and 6, warranting the assumption that a very different 

 acidic fermentation has taken place in these bags from that which 

 occurred in the remaining bags. It is clearly impossible to assume that 

 the non-volatile acid in these bags was lactic acid wholly. In this con- 

 nection, it is interesting to remember that bags 1, 2 and 3 contained 

 unwilted material, and bag 6 slightly wilted material, and that the 

 fermentative processes in these bags went on therefore under much 

 moister conditions than obtained in the other bags. The question is 

 worthy of further investigation, since excellent samples of silage were 

 obtained from bags 1, 2 and 6. It is probably incorrect to assume that 

 lactic acid is the only non-volatile organic acid which may arise as a 

 result of fermentative changes in the silo. 



IV. Changes suffered bi/ the crude fibre constituent. 



In every case, a loss of crude fibre was recorded as a result of ensilage, 

 the loss varying from about 5 per cent, in the case of the unwilted oats 

 and tares to about 10 per cent, in the case of the wilted material. In 

 the case of the spoilt sample in bag 8, the loss of crude fibre was as much 

 as 16-5 per cent, of the original amount of fibrous constituent in the bag. 



The question arises as to the type of action in the silage process 

 which results in the disappearance of crude fibre. The explanation is 

 probably to be found in work carried out by Voelcker^, who found that 

 the following change occurs when straw chaff is mixed with a small 

 quantity of green rye or tares (1 ton straw chaft' to about 1 cwt. of rye 

 or tares) in the spring or summer and the mixture is allowed to ferment 

 until the autumn. 



The untreated straw contained 23-7 per cent. N.-free extractives and 

 54 per cent, crude fibre. 



The fermented straw contained 45-8 per cent. N.-free extractives and 

 34-5 per cent, crude fibre. 



1 Voelcker, ./. of the R. Agric. Soc. of Eng. 7, 85, 1871. 



