Effect of Moisture Content on Corn Silage Effluent

S.C. Fransen
Washington State University, Prosser, Washington

Effluent from corn silage harvested at excessive moisture content represents a loss of valuable nutrients and poses an environmental risk because the effluent is very rich in soluble nutrients. In our study there was a curvilinear relationship between corn silage moisture content and amount of silage effluent (Fig. 1). Silage containing 20% dry matter lost as much as 10% of total silage weight as effluent. As dry matter increased above 20%, there was a sharp decrease in effluent, and very little effluent was lost from corn silage with more than 30% dry matter. At equivalent dry matter contents, corn silage produces more effluent than grass silage. Dry feedstuffs can be added to wet silage to reduce effluent; we found that beet pulp was most effective, alfalfa cubes was intermediate and barley grain was least effective in reducing effluent from wet corn silage. Silage with alfalfa cubes contained somewhat more lactic acid and less acetic acid than the silages with the other additives. 

Figure 1.  Relationship between moisture content of corn silage
at harvest and loss of effluent.