238 STATE BOARD OF AGRICULTURE. 



and aerobically. Bacteria of tlie Bad. lactis acicli type were easily 

 isolated from the plates from silos G and 7 but bacteria of the Bad. 

 tulgaricum type could not be reisolated. There was evidence of the 

 presence of acid and gas producers in the 37° litmus dextrose plates 

 from silo 9, but in silos 10 and 11 only acid but no gas producers were 

 found on the plates. It is to be regretted that more detailed bacteriologi- 

 cal studies could not have been made. The indications are that if bacteri- 

 ological analj^ses are made soon enough on inoculated silage that or- 

 ganisms resembling the pure cultures added, can be detected. How- 

 ever, as previously stated, none of the pure cultures employed appeared 

 to have the effect of inhibiting or suppressing mold growth, nor is it 

 logical that such would be the case. The silage fermentation is largely 

 an acid fermentation, the acids formed being mainly lactic and acetic. 

 These common organic acids in the strengths found in silage are easily 

 and readily attacked by molds of many species under aerobic condi- 

 tions, such as are always found at and near the surface and occasion- 

 ally in i^ockets distributed throughout the depths of the silage. It is 

 doubtful whether any bacteria can produce acid of sufficient strength 

 in silage or in other naturally fermenting material to inhibit mold 

 growth. Bacteriological studies of a sufficient number of exi^eriments 

 have not yet been made, however, to determine whether pure cultures 

 used as inocula will eventually control the fermentation or whether 

 the natural microflora of the silage instead will determine the type of 

 fermentation occurring, in spite of the kind and amount of pure culture 

 added. As time permits this phase of silage inoculation will be studied. 



The silos 14 to 17 inclusive containing larger proi^ortions of salt were 

 opened this spring. The top silage to the depth of nearly two feet had 

 to be removed before the typical acid odor was apparent. Molds were 

 found in the first foot and then the next portion appeared all right, but 

 the acid odor was lacking. Silage having a salt content of more than 

 1-80 at first physiced the calf and sheep to which it was fed but this 

 effect was not produced after the first few feedings. These two animals 

 in time refused to eat much of the more heavily salted silage so its 

 feeding was discontinued. Bacteriological studies were made only 

 from silo 14. 



Pure cultures of acid-producing bacteria were isolated from some of 

 the silos and their acid production determined in dextrose, sucrose and 

 lactose broths by means of the colorimetric H-ion concentration method 

 in order to determine the most active and strongest acid producers. 

 The organisms having the best qualifications are to be used in further 

 inoculation experiments. The results of the tests are as follows: 



