GRASS SILAGE 9 



Another method that is said to give good results is to sow oats thickly over 

 the top of the mass. The mat of roots from the sprouting grain seems to be 

 effective in excluding the air. 



Intervals between spells of filling should not be longer than 48 hours at the most, 

 and preferably not more than 24 hours, as the unprotected green material spoils 

 rapidly. Some operators have found that adding water between fillings helps 

 to keep spoilage down. 



When the filling job is completed, the cutter, blower, and blower pipe should 

 be thoroughly flushed with water from a hose to clean off any residue of molasses. 



Chemical Changes and Losses Taking Place in the Silo 



The changes are similar to those which occur in corn. The most important are: 



1. Breaking down of considerable of the protein to its constituent amino 

 acids; production of some ammonia. 



2. Formation of lactic and acetic acid from the sugars and starches; incidental 

 production of some methane, alcohol, and carbon dioxide. 



Losses may be classified into: 



1. Unavoidable losses, due to the escape of the gases methane and carbon 

 dioxide, noted above as products of fermentation. In a tight silo with silage well 

 packed and the top properly sealed, most of the loss will be in this category. 

 It may amount to as much as 12 percent of the total weight of the crop, but is 

 usually between 5 and 10 percent. 



2. Losses which can be controlled, due for the most part, to seepage and 

 growth of molds. Some seepage is inevitable, but it may be kept at a minimum 

 by not harvesting the crop when it is very wet, by allowing very succulent crops 

 {Ladino clover, for instance) to wilt before storing, and by putting the less succu- 

 lent material in the bottom half of the silo where it will absorb the juices seeping 

 down from the upper layers. 



That seepage need not be a cause of serious losses is shown by records taken 

 at the State College during the past season. In order to obtain such records, a 

 concrete floor was constructed in a silo of 100 tons capacity, with one central 

 drain leading through glazed tile with watertight joints, to a catch basin outside 

 and below the base of the silo. To insure free drainage, a cast-iron dome was 

 placed over the strainer at the inlet of the drain. A self-recording device for 

 measuring flow of liquid and for sampling the liquid was placed under the drip 

 from the tile in the catch basin. 



The amount of liquid which drained off was slightly more than 28 gallons, or 

 about two thirds of a barrel. The amount of solids in this liquid was determined 

 on seven different occasions and averaged almost exactly 5 percent, or a total 

 of not quite 12 pounds of solid substance lost by seepage from over 82 tons of 

 silage. Practically all of this drainage occurred during the first ten days after 

 beginning to fill the silo, most of it in the first six days. 



Growth of molds may be the cause of serious loss, but can be kept at a minimum 

 in a tight silo with the precautions already noted in the sections on "Filling" 

 and "Sealing." 



Changes in composition of grass, depending upon whether it is made into hay 

 or stored as silage, are shown in Table 1 . A field on the State College farm, having 

 a uniform stand of grass was divided into halves at silo-filling time in June 1937. 



