INFLUENCE OF FERMENTATION ON THE STARCH 

 CONTENT OF EXPERIMENTAL SILAGE 



By Arthur W. Dox, Chief in Chemistry, and LESTER YoDER, Assistant Chemist, Iowa 

 Agricultural Experiment Station 



INTRODUCTION 



It is not definitely known, though sometimes assumed, that poly- 

 saccharoses undergo changes during the formation of silage from green 

 corn. The work reported in this paper was undertaken to determine 

 any changes the starch might undergo together with the nature of these 

 changes and their relation to other important reactions occurring in silage 



fermentation. 



PREVIOUS INVESTIGATIONS 



Results of acidity, alcohol, and sugar determinations have been re- 

 ported by Dox and Neidig (5, 6)* and Lamb (9) in investigations extending 

 over initial fermentation periods of 30 days and less. Acids and alcohol 

 are rapidly formed at the expense of the sugar, the rate and extent of 

 the changes depending largely upon the nature of the corn. 



Babcock and Russell (2), Hart and Willaman {8), and Esten and 

 Mason (7) have made important contributions bearing upon the common 

 changes occurring in silage. 



No investigations concerning the starch of corn silage have been re- 

 ported. Statements are made in an article by E. J. Russell {13) of the 

 Rothamsted Station to the effect that bacteria are present which attack 

 the less resistant celluloses and that the disappearance of some less 

 resistant celluloses is a characteristic silage change. 



EXPERIMENTAL METHODS 



The plan followed by the writers provided for the examination of 

 normal experimental silage at various stages of fermentation. Field 

 com still green, dented, and about at its glazing stage, cut at about 

 9 a. m., was taken in bags from the farm silage cutter, brought to the 

 laboratory, and further chopped in the laboratory feed cutter. The 

 chopped silage was then thoroughly mixed, and 2.5 kgm. were packed 

 uniformly into each of 10 wide-mouthed glass jars at 3 p. m. of the same 

 day. The jars were then covered, sealed with paraffin, provided with a 

 valve escape for gases, placed in a large box, and well insulated from 

 exterior temperature influences. On the first day the temperature of 

 the silage rose to 29° C. It remained there for two days, then dropped 

 gradually to room temperature by the seventh day. 



' Reference is made by number (italic) to "Literature cited," pp. 178-179. 



Journal of Agricultural Research, Vol. XIX, No. 4 



Washington, D. C. May i5. 1920 



ud Key No. Iowa-7 



(173) 



