Agrarian Marketing Corporation

Some argue that Kingda Ka (Six Flags Great Adventure – NJ) is the fastest, most vertical roller coaster in the US. Dairymen likely thought they were experiencing just that last year when mycotoxin levels in corn, wheat, and silage soared to record-breaking heights. And now, one hears a collective sigh of relief from the industry as lower, more sporadic, and more typical levels of DON, zearalenone and others are reported in late 2010. But like most roller coasters, that ‘first’ hill last year was not the last! Mycotoxins have historically shown seasonal rises and falls. Generally, growing and stored feedstuffs are most vulnerable when temperature changes are most extreme; therefore, spring and fall are the times mostly likely to produce mycotoxin spikes. Even under laboratory conditions, the greatest yields of mycotoxins are achieved when mold cultures are grown under variable temperatures rather than steady temperature incubations.

Go back to 2009 again. Many of the regions experiencing the highest level of toxin contamination in corn were also those which had wet conditions at normal planting time, delaying getting the seed into the ground, and, then, wet fall with delays in harvest, sometimes to the point where first snows had fallen. From the more normal 250-1000 ppb DON, corn tests showed new harvest corn reaching as high as 90,000 ppb! And reports on silage from various locations also showed higher-than-average DON levels. And consider that ’09 crop issues left specific toxigenic mold spores in the fields that are subsequently replanted in corn. Yes! When we put the same crop into the same field year after year, we are promoting the rise of adapted mold strains; if they are also toxin producers, each subsequent crop is at higher risk. In time, this favors those strains capable of producing the higher toxin levels under wider ranges of environmental conditions. Expect, then, that whatever the winter of 2010-11 brings, spring warming plus the broader range between day and night temperatures will likely produce a typical round of increased spoilage/mycotoxin contamination of stored feedstuffs (silage, shell corn, etc.).

And, always keep in mind that when we submit samples periodically for testing, we are testing for a tiny number of the many possible contaminating mycotoxins in feedstuffs. A growing number of investigators are now cautioning that dairy issues are likely correlated to two of the toxins produced by a species of Penicillium which thrives in corn silage. Mycophenolic acid and roquefortine C occur almost as frequently as DON and often in amounts significantly higher than that ‘marker’ toxin. Even worse, except for the generic symptoms (lowered milk production, irregular manure, increasing SCC, reproductive failures) responses specific to mycophenolic acid and roquefortine C have not been determined. Also, there are no rapid, antibody-based assays for those two toxins and commercial labs are not prepared to offer test options for them. Even a low test for DON (e.g., <500 ppb), a Fusarium toxin, should leave us wondering if some other potentially more devastating fungal poisons are present in our silage. Producers need to be considering now, as winter is just fixing its grip on the country, how they will prepare for and deal with those circumstances so that herds are not impacted by sudden shifts in background mycotoxin levels during the spring. The most successful remedy to-date is the application of specific L-Form bacteria that inhabit the cow’s intestinal epithelium and act as gatekeepers, scavenging absorbed toxin and signaling the normal epithelial cell’s own regulatory systems to exclude more toxin.

Mycotoxins and Reproduction

Feeds, containing mold-produced spores, are a growing concern for dairy producers. Mold spores reduce the nutrient quality of grain and produce secondary metabolites, known as mycotoxins. These poisons affect the digestive, immune and reproductive functions of the dairy cow and can allow other diseases to invade from an already depleted immune system. While there are hundreds of mycotoxins, only a few can be adequately identified for further study. Researchers now understand that these toxins, even at low levels and in combination with others, are far more debilitating than high levels of individual toxins due to a cumulative effect.

Growing, Harvesting, and Management of Feeds

Key soil born molds, such as fusarium and aspergillus, increase during periods of extreme weather. These weather changes, along with current economics of feed crop production, have changed tillage and production practices allowing increases in mold growth potential. The cool wet weather in many parts of the country during much of this year’s growing season has set the stage for micotoxin challenges on many dairies this fall and winter.

During the life-cycle of molds, a spore (seed) is produced. And during this process, many chemicals are produced, with some being toxic to animals. In silage, once re-exposed to oxygen, molds start added growth at an incredible rate. Common practices as loosening silage for feed-out or single daily feed mixing, allows mixed feeds an excellent opportunity to produce high toxin levels before consumption.

Nutrition, Mycotoxins and Reproduction

Nutritional factors, such as high MUN’s (Milk Urea Nitrogen), acidosis, and mycotoxins, all can have a negative effect on herd health status because they stress the immune function of the cow. Any damage to immune function debilitates reproductive performance. It may be clinical or sub-clinical but it happens every time. Optimum reproduction can only be achieved when the affect of mold produced mycotoxins, along with other nutritional problems, are controlled.

Preventive Action

Mycotoxin testing is one option to determine the level of challenge. Dairymen should take action when suspect feed ingredients are being fed, symptoms are observable, or tests show the presence of multiple toxins at any level.

More and more dairies are routinely using Nutrisound® from Agrarian Marketing Corporation to maintain high reproductive levels and reduce herd health challenges caused by undetected moldy feed ingredients or related nutritional problems.