Nutritionist Rick Lundquist’s dairy client used a new technology to prevent the development of aflatoxin in his corn silage crop - and it appears that it worked.
Last month in this column, I discussed the problems many producers were having with aflatoxin contamination of their 2013 corn silage crop.
Some dairies in the Southwest had to dump milk that tested over the legal limit. Many dairies are feeding clay products and limit-feeding the corn silage to reduce the risk of aflatoxin.
One of my clients used a new technology to prevent the development of aflatoxin in his corn silage crop - and it appears that it worked. He actually applied Aspergillus flavus, the fungi that produce aflatoxin, to his corn crop while it was growing in the field.
Aspergillus flavus and Aspergillus parasiticus are fungi that are ubiquitous in soil and produce spores that are spread by wind and insects. The spores attach to crops such as corn, cotton and peanuts and then germinate if environmental conditions are right. The fungi can also live on crop residues from previous growing seasons, especially under no-till management. Temperature between 77 and 108 F are optimum for development. The fungi grow under these conditions and can produce alfatoxin on plants stressed from heat, drought or insects.
My client applied a commercial product called Afla-Guard (manufactured for Syngenta), which contains a strain of Aspergillus flavus that does not produce aflatoxin. The product is on a barley carrier. Moisture activates the fungi to produce spores, which are then spread by wind and insects throughout the field and on the crop. The "nontoxic" strain of the fungi compete with and displace the naturally occurring toxin producing strain, thereby reducing the risk for aflatoxin development in the crop. Research by USDA-ARS showed up to 85% reduction in aflatoxin with the product.
The product is applied by ground or aerial broadcast methods. For corn, recommendations are for application between about 14 days before tassling (or when about 10-12 visible leaf collars appear) up to active silking.
My client’s costs for the product and for the aerial application were less than $1.00 per ton of silage. This is less than what we would spend on binders trying to deal with aflatoxin in the feed. His silage tested very low or completely clean for aflatoxin. We didn’t have any control plots, but the local lab commented that his was one of the very few corn silage samples in that area that didn’t have aflatoxin.