Lebanon Crop Management Video


01 September 2012

Corn Silage and Disease Considerations

Del Voight- Penn State Extension
There are many questions as to the silage quality. Corn Kernels are germinating on the plant in some fields, various diseases are being observed on the ears as well as the stalks.  The decision will need to made on a case by case basis with inspection of  fields for which is the most prevalent disease and even then it will come down to a quality analysis and a mycotoxin screening. 

Forage Quality: Nutrient Composition

Page also has some factsheets on Mycotoxins, Nitrates, and other toxicity problems.
Is the dust safe?  Greg Roth related a recent article dealing with the dust. The bottom line is you will not know if the dust is safe to you or your workers so proceed as if it is not safe and use a respirator.  Flood corn silage polluted dust
"Can I chop and feed this stuff?"

In most cases "Yes" the grower can chop and feed this stuff. Soil on the plants will raise the issue of Clostridium growth and in a recent conversion with my veterinarian we vaccinated all my cattle with Ultrabac 8 that will prevent toxic affects from soil that might be on my fall pastures. He related that he is vaccinating all the dairy herds for this purpose of the likelyhood of soil being mixed into the forages.  Again testing forages is essential for mycotoxins.  There should be no feed toxicity issues with common rust and smut for corn silage. Mycotoxins can develop and are associated with temperature extremes. Due to the stresses encountered by the crop and the diseases expressed, quality as measured by milk per ton and milk per acre will likely be decreased.
Craig R. Grau  of Wisconin Extension had the following comment on a thread I read.  The key decision will be to ensile at the proper moisture for the storage structure to ensure adequate fermentation and preservation. That will likely be tricky due to the variabilty of the plants in the field.
Once the field is ensiled, a quality analysis should be done to see how badly quality was affected. A mycotoxin test should also be performed. Little research is available for multiple stress effects on silage quality. It may be correct and prudent that feeding should be limited to heifers, but a forage quality analysis will give the grower and nutritionist some confidence as to what kind of forage they are delaing with.
We had some reports of black dust on the silage could be smut due to the previous wind damage.  Paul Esker also from Wisconsin Extension wrote the following in another thread I read.... Smut galls are not poisonous to animals, but they will increase the dust content of dry matter. The acids in silage are typically enough to kill the spores. Interestingly, if the stalks, leaves, and ears are fed to animals, the smut spores can survive through the alimentary canal and be passed through into the manure. If this is spread onto fields, this can become a source of inoculum for infecting new corn plants. Also, smut is considered a delicacy in many parts of Central and South America. As for rust, the main concern would be if there is some decrease in palatability. Much of the work has examined the effect of southern rust (Puccinia polysora) and lower silage quality (mainly due to early plant death). If the forage is ensiled, the fermentation process would be expected to kill the fungus, thus reducing the concern of an unpalatable food source.

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