SILAGE SOILAGE THE PREPARATION OF FEED 257 



carbohydrates are attacked to only a small extent. It is due to this that 

 well-matured corn or sorghum makes less acid silage than immature 

 plants, which contain more sugar. Even tho an excess of sugar is present, 

 the fermentation comes to an end at length, for sufficient acid is finally 

 produced to prevent both the further growth of the bacteria and yeasts 

 and the action of the plant enzymes. During the fermentation processes 

 the temperature rises somewhat, but if the mass has been well compacted, 

 so that but little air is present, the temperature in the interior of the silo 

 rarely reaches 100 F. The changes are therefore far less extensive than 

 those which occur in the making of brown hay. (334) 



Not only does the accumulation of acid automatically check the further 

 action of the acid-forming enzymes and bacteria, but it also prevents the 

 growth of undesirable putrefying bacteria, such as cause the decaying of 

 meat. The poor-quality, foul-smelling silage which often results when 

 such legumes as alfalfa, clover, or soybeans are ensiled alone is doubt- 

 less largely due to the fact that there is not enough sugar present in the 

 plants to yield sufficient acid to check the growth of these putrefying 

 bacteria. The high protein content of these plants also favors putre- 

 faction. 



After a few days the silage-making processes cease, and no appreciable 

 changes will take place so long as the air is excluded. Instances are on 

 record where silage made 12 to 14 years before has been found to be of 

 excellent quality. 



Tho the conversion of sugar into organic acids is the chief change 

 which takes place in good silage, other decompositions also occur to some 

 extent. A considerable part of the protein is broken down by enzymes 

 into amino acids (11), the silage sometimes containing 2 or 3 times as 

 much of these cleavage products as the original fodder. However, as 

 this splitting of the protein into simpler compounds is similar to the 

 digestion which takes place in the digestive tract of the animal, we need 

 not suppose that the nutritive value is thereby necessarily impaired. (49) 



405. Steaming silage. It has sometimes been advocated that forage be 

 steamed immediately after placing it in the silo, on the ground that the 

 bacteria, yeasts, and enzymes are thereby destroyed, and the more or 

 less perfectly sterilized mass thus preserved with little or no fermenta- 

 tion. However, Withycombe and Bradley found in digestion trials with 

 cows at the Oregon Station 3 that steaming corn forage after ensiling 

 reduced the digestibility of the dry matter 16 per ct., the crude protein 

 91 per ct., the ash 79 per ct., and the fiber, nitrogen-free extract, and fat 

 to a slight extent. Hence, tho the steamed silage was admirably pre- 

 served and contained only half as much acid as ordinary silage, its feed- 

 ing value was greatly reduced. (83) 



406. Requisites of a good silo. 1. Air-tight walls. The silo walls must 

 be air-tight, for if oxygen gains entrance the fermentations will con- 

 tinue and molds will grow, spoiling the silage. Such action takes place 



3 Ore. Bui. 102. 



