Denise Schwab from the Iowa State Extension Beef Program shares her thoughts on feeding this year's drought damaged corn as silage:
"I think Variation is the key word for this year's crop. A lot depends on when and how long the plant was stressed. We have only seen a few silage/green chop analysis tests so far but here are a few observations. On average, they don't look too much out of the ordinary, however individual samples are highly variable from the average.
1. Protein appears to be higher than normal corn silage, as would be expected.
2. Starch is lower as expected.
3. Nitrates are highly variable with some being close to the caution level.
If the corn has ears with close to average yields the silage will be a great feed, and possibly will be the major feed for beef cattle here in Iowa. If the field had few ears, the silage will be lower in starch and feed energy which is probably OK for beef cows but will need to be supplemented with an energy feed for feedlot cattle.
Some grain will likely be light test weight this fall with less total starch. However, corn that is 40-45 lb. test weight or greater will still have near normal feed value. One of the beef industries major supplemental feeds in the last few decades has been corn co-products, either gluten to distillers grains. Currently the demand for these feeds is high enough that both the price and the availability of these feeds are a challenge, and that likely will carry on into the rest of the year. So basically the major supplement needed will be additional energy feeds."
Another serious concern for this year's drought damaged crop is Aflatoxin. Aflatoxins thrive during hot, dry summers and can, in some cases, be fatal to livestock fed contaminated corn. The most abundant strain, aflatoxin B1, is carcinogenic and can appear in the milk of dairy cows fed affected grain. Below is a table outlining acceptable tolerances in feeds for various livestock provided by the Iowa State University Extension and the Food and Drug Administration.
FDA guidelines for acceptable aflatoxin level in corn based on intended use (www.fda.gov):
||Aflatoxin level (ppb)
|Milk (Dairy Feed)
|Corn of unknown destination
|Corn for young animals
|Corn for dairy cattle
|Corn for breeding beef cattle, swine and mature poultry
|Corn for finishing swine
|Corn for finishing cattle
Click here for more on Aflatoxin.