Time to harvest corn silage is fast approaching. When evaluating whether to harvest a field for silage or grain, the issue of how to price and value the corn is often a point of uncertainty and is subject to variability. Corn silage is usually priced at one of three points - standing in the field, packed in the silo, and delivered in the bunk.
UNL research has shown that corn silage priced standing in the field before harvest should be valued at 7.65 x the price per bushel of corn where a ton of corn silage is harvested at 60-65% moisture. This multiplier value is consistent regardless of corn price. If we estimate corn at $3.50 per bushel for a nice round number, $3.50 x 7.65 = $26.78 per ton in the field. This accounts for harvest grain price, not having to combine or haul grain to market, increased grain price due to storage, and the cost of silage storage. When estimating costs in the silo, harvest, hauling and packing expenses can vary. The 2024 Nebraska Farm Custom Rates publication showed an average custom rate of $13.50 per ton for chopping and hauling. At $26.78 per ton in the field plus $13.50 per ton for harvest, we come out to $40.28 per ton in the pile. When $3 per ton is added for storage expense, the price per ton is $43.28.
When valuing silage out of storage and into the bunk, remember the ensiling process will cause shrink and dry matter loss from 10-20% or more from when silage is packed and stored until it is removed to be fed. With 10% dry matter
shrink, the value of silage delivered to the bunk would be $47.61 per ton. If the shrink loss is 20%, then the value of silage would be $51.94 per ton.
Excellent information is available on the beef.unl.edu website illustrating the impact of covering, packing, and other management factors to decrease silage shrink.
One final thing to take into consideration. Harvesting drought-stressed corn as silage may be an option to salvage the crop and produce needed forage.
The quality of drought-stressed corn silage can vary but is usually 85-95% the energy value of regular corn silage.
A good measure to consider is doing a starch analysis. If you divide the starch % (DM basis) in corn silage by 0.70, that gives you an indication of the grain content as a percent in silage.
With drought stressed corn, caution should be used in harvesting if high nitrates are present. While ensiling can reduce nitrates by 40-60%, cutting high in fields considered at risk for high nitrates may help reduce nitrate levels all be it at a reduction in yield.
