758 MAIZE 



chap, silage arc: fatty acids, hydroxy-acids, amino acids, basic 

 xv - diamino acids, purin, and other bases besides the ordinary 

 constituents of the plant cell, the celluloses, protein, etc. The 

 non-nitrogenous acids are not found in maize at the time of 

 cutting, and the nitrogenous acids, though they arc found, 

 occur to a smaller extent than in silage. 



The characteristic silage changes are the disappearance of 

 sugar, of some less resistant celluloses, and of part of the 

 protein, and the formation of the bodies enumerated above. 



Three agents appear to be involved in making silage : the 

 living maize cell, the enzymes, and micro-organisms. It is 

 considered that the two former bring about the primary and 

 essential changes, the latter only secondary and non-essential 

 changes. 



The formation of acetic and butyric acids appears to be 

 a respiration effect, and comes about when the living cell is 

 deprived of oxygen. Sugar disappears during the process. 



The decomposition of the protein and nucleo-protein is 

 effected by enzymes present at the time of cutting the maize, 

 which can go on acting in the silo even after the cell is dead. 

 Characteristic products of protein-hydrolysis were identified in 

 the silage. 



These are regarded as the primal'}' and essential changes. 

 Bacteria are, however, always present, and attack the less re- 

 sistant celluloses, the products of protein-hydrolysis, and no 

 doubt other substances as well, but not the resistant fibre. 

 Typical products of bacterial activity were found — formic acid, 

 higher fatty acids, humus, and amines. 



The growth of mould is inhibited except at the surface 

 layer where fresh air has aqcess. Here the changes are funda- 

 mentally different ; there is no development of acetic or 

 butyric acids, the mass is alkaline ; non-protein material already 

 existing in the maize is converted into protein, and there is 

 also a loss of nitrogen. 



731. Changes in the Protein due to Ensiling. — The New 

 Jersey (U.S.A.) Station (Bull, 122) found that ensiling resulted 

 in the conversion of about two-thirds of the more complex 

 albuminoids into the simpler amides. " Silage often contains 

 nearly half its nitrogen in amide form, while dry fodder-corn 

 has not more than from 1 2 to 15 per cent of its nitrogen in 



