6 MASS. EXPERIMENT STATION BULLETIN 425 



Urea proved entirely unsuitable as an addition to silage. It was used not so 

 much with the idea that it might have a preservative action as to increase the 

 nitrogen content of the silage and hence its potential protein level for ruminants. 

 Chemical examination of the silage showed that a considerable portion of the 

 urea was converted into ammonia and lost in the leachings from the silo. The 

 silage had a very objectionable odor and was unpalatable to cows. 



To sum up briefly the present status of knowledge on the use of silage pre- 

 servatives — they are not needed for corn, nor for the small grains when reasonably 

 mature (dough stage), nor wherever it is feasible to practice wilting of grasses 

 and legumes. Where for any reason wilting of grasses and legumes cannot be 

 practiced, the preservatives which give assurance of a good quality silage are 

 molasses or some kind of ground grain. It should perhaps be added that another 

 alternative to wilting the grass, is to let it grow to such a stage of maturity that 

 its moisture content is down to 70 percent or less. This alternative should be 

 used only as a last resort because the nutritive value of the grass, especially the 

 vitamin and mineral content, is lowered progressively as the crop approaches 

 maturity; also such mature crops are more easily made into hay, a fact which 

 lessens the motive for storing them as silage. On the other hand, such relatively 

 mature material would be more palatable and probably more digestible as silage 

 than as hay, provided it is not too mature to pack well. 



Harvesting Methods 



Where wilting is practiced, the crop must be left in the swath for from one or 

 two hours to half a day or more, depending on weather conditions and the suc- 

 culence of the crop. Under such conditions the best rig is the side-delivery 

 rake followed by the green hay loader. When a green hay loader is not available, 

 an ordinary hay loader can be used on this partly dried material provided cau- 

 tion is used not to roll up too large a windrow with the side-delivery. 



Where wilting is not practiced, the mower may be equipped with a windrowing 

 attachment for the cutter bar which eliminates the raking operation. The green 

 hay loader is essential for this unwilted material — the standard hay loader is 

 subject to too much breakage with heavy green crops to be practical. The same 

 could be said of the earlier types of green hay loaders but many improvements 

 have been made since these were first put out and more recent types are of more 

 rugged construction and improved design. The raker bar cylinder type with 

 metal deck seems now to be the accepted design. 



The most recent development in green crop harvesting is the field chopper 

 which combines in one tractor-powered outfit the three operations of cutting, 

 chopping, and loading. These machines have reached the practical stage and are 

 reported as giving satisfaction with all types of forage crops from corn to alfalfa. 

 Such an outfit does away with much hand labor and the need of a chopper at the 

 silo, only the blower-elevator being required. A field chopper cannot be operated 

 to advantage on small fields, and obviously wilting cannot be practiced where 

 one is used. 



Control of Seepage 



One problem that has arisen on many farms where grass silage is stored has 

 been that of seepage control. Oftentimes succulent green crops are stored with- 

 out wilting, and in some cases additional water is used, either for dilution of 



