Making Silage from Late-Season Hail-Damaged Corn
The first step in dealing with hail damage is to contact your insurance agent to learn what is required to meet obligations for hail or revenue insurance.
High moisture feed options to get it out of the field earlier. Making hailed corn into corn silage can be a good option for those with cattle or who have neighbors with cattle. For those with feedlot cattle or who can sell to neighbors with feedlot cattle, high-moisture corn or earlage are options. Due to the dilution effect of the plant material, silage is likely a better option for ears with mold.
Is there visible mold growth? The good news is that the most common fungi observed so far this year has been Diplodia ear rot which does not have a mycotoxin associated with it. However, Fusarium ear rot also has been observed and fusarium species can produce mycotoxins, including fumonisin, vomitoxin (DON), and/or zearalenone.
When properly done, the ensiling process will stop mold growth; however, it will not destroy any mycotoxins already produced. Thus, mycotoxin testing is suggested. If needed, non-contaminated feeds can be blended into the diet to reduce potential negative effects. For more information see the Nebraska Extension NebGuide, Use of Feed Contaminated with Fungal (Mold) Toxins (Mycotoxins) (G1514).
Nutrient content of late season hail damaged corn silage. By late in the season, most of the grain production has occurred. Thus, if only leaves and the upper stem have been lost, grain content of the silage may actually be greater than under normal harvest conditions. Grain content relative to forage can be estimated after putting up the silage by getting a starch analysis and dividing the percent starch by 0.7. For instance, if the analysis showed that the silage was 35% starch, it would be estimated at 50% grain (0.35/0.7). While the grain content may be increased, the digestibility of the plant material (fiber) may be decreased as stalk may make up a greater proportion than normal. Thus, a nutrient analysis of the silage will be important for effective use in rations.
The potential yield is important in determining cost effectiveness of corn silage. In corn that is between ¾ milk line and black layer, the leaf makes up about 15%-20%, the stalk 20%, and the ear 55-60% of the dry matter (DM) yield. The top one-third of the stalk constitutes only 2% of the total DM yield. Thus, with loss of leaves and the upper part of the stalk due to hail, corn that would have yielded 10 tons of DM/ac would yield around 8 ton/ac. Under this scenario silage production would likely be a cost-effective option. If some ear loss occurred or if some plants are broken so that they can’t be harvested, the lower yield potential will increase the harvesting cost. If cost of silage harvest is $75-$100/ac (as an example) and yield was 10 ton/ac, the harvest cost would be $7.5-$10 per ton. With loss of just the leaf and upper stem, the cost per ton increases to around $9-$12.5 per ton. However, if 25% of the ears were also lost in addition to the leaf and upper stem, the silage may only yield 6.5 tons DM/ac and harvest cost would be 50% more than normal at $11.5 to $15 per ton.
Moisture of the harvested material is very important. For corn silage, the target for the material to be ensiled should be 60% to 65% moisture (plant included). Looks can be deceiving since the ear and bottom portion of the stalk make up the majority of the material. The brown leaves (that were damaged by hail) can give the appearance that the plant is drier than it actually is. Harvesting the whole plant, chopping it, and drying it down is the only way to get a good estimate of moisture content. For more tips on making good silage see the BeefWatch article Silage Considerations.
Pricing of silage when selling to neighbors with cattle can be difficult. First, all the feeding risks associated with the mycotoxins are on the cattle producer. Second, not knowing yield and thus, harvest cost per ton, makes pricing challenging. For standing crop and normal silage, the price for silage in dollars/ton (as-is) is approximately 7.65 times the corn price; however, that assumes normal yield and would need to be decreased if harvest cost per ton is dramatically greater.