Dec. i6, igis BacteHological Studies on Alfalfa Silage 



589 



f^G. 



Fig. 



-Graphs showing protein sparing effect of carbohydrate 

 in alfalfa-silage fermentation, second series. 



The problem was discontinued at this point on account of the author's 

 entering other work for the period of the war. As a result, the causa- 

 tive agents of the protein decomposition were not determined. How- 

 ever, the following suggestions pertaining to this question are offered: 



It is recognized that the decomposition must be the result of microbial 

 or plant-enzym activity or their associative actions. Previous publica- 

 tions issued from this 

 laboratory mention the 

 importance of microor- 

 ganisms in silage fer- 

 mentation (5, 6). From 

 these results it is con- 

 cluded that the major 

 fermentation processes 

 in silage ripening are 

 the result of microor- 

 ganisms. That plant 

 enzyms are active is not 

 doubted, but their ac- 

 tivities are of minor 

 importance. Lamb in 

 a recent paper on 

 corn-silage fermentation (12) concludes (a) that bacteria are mainly 

 responsible for the acid production and the disappearance of sugar; 

 (b) that alcohol results from enzym activity first, but later by yeast 

 fermentation; (c) that protein decomposition is caused by enzyms first, 

 and later by microorganisms; and (d) that carbon dioxid is liberated by 



enzymic or respiratory 

 changes primarily, but 

 that yeasts are influ- 

 ential after the first 

 day or two. 



Observations of si- 

 lage made under lab- 

 oratory conditions at 

 this Station indicate 

 that yeasts are the 

 primary factors of al- 

 cohol and carbon- 

 dioxid production. In 

 the study of the mi- 

 crobial flora of silage it was noticed that as a rule the curve of yeast devel- 

 opment indicated a very rapid increase of yeast cells within the first two or 

 three days followed by a rapid to gradual decrease. It was further no- 

 ticed that during the period between 12 and 72 hours after siloing the 

 material underwent a violent fermentation, with the liberation of large 

 amounts of carbon dioxid. During this early fermentation considerable 



Fig. 3. — Graphs showing protein-sparing effect of carbohydrate in 

 alfalfa-silage fermentation, third series. 



