What a winter we had- mild temps, low precipitation and no blizzards to conquer. It seems there was nothing to complain about this season.
While the weather outside was excellent for keeping our livestock healthy and productive, it wasn’t so great on the inside of our feed bins and silos. As many farmers across the Midwest are finding out, their corn stored away since the fall harvest is now coming out with higher levels of mold and discolored kernels. After a winter that wasn’t cold enough or long enough to protect the grain from fungal infection, last year’s harvest is at an elevated risk for mold and mycotoxins.
Mycotoxins, harmful toxins produced by molds, can create a variety of health problems for animals depending on species and type of toxins identified. In swine and equine, there is a higher sensitivity to contaminated feed and feed
avoidance is a common symptom of mycotoxicoses in these animals. Ruminant animals are often resistant due to microorganisms in the rumen that can degrade toxins before they enter the bloodstream. Harmful effects are observed however, in high producing dairy cows. Reduced milk production, impaired reproduction and immune suppression in cows are possible effects of mycotoxicoses.
How did these toxins get into our bins? In any fermentation storage system, temperature and the presence of moisture is sufficient for toxin production. However, oxygen is the actual component which turns mycotoxin production on or off during storage.
According to the site www.knowmycotoxins.com, the amount of mycotoxins in contaminated silage samples increases as the ensilement method changes from airtight, upright silos to concrete capped and uncapped silos. The highest forage concentrations of mycotoxins are found in horizontal storage methods such as bunker silos and feed piles which are left open to oxygen.
Where greater amounts of mycotoxins are found, poor management of the upright or bunker silo has resulted in oxygen entering the stored feed. In scientific studies, well managed bunker silos, covered with plastic and weighted with tires, did not have significantly greater levels of mycotoxins than well managed upright silos.
In a plastic covered storage system, oxygen penetration is slowed but not eliminated. The longer the silage is stored, the greater the opportunity for significant fungus growth and mycotoxin contamination.
Silage and stored feed are perfect energy sources so producers, nutritionists, and veterinarians should be aware of storage molds, particularly the Penicillium species, because of their ability to impact rumen function. Since a test is not commercially available currently to test for Penicillium mycotoxins, running a mold test and identification can be a useful way to identify the presence of these molds.
Here is a checklist of some other items to consider when storing feed during a mild winter:
1. Check grain for mold growth regularly.
2. Patch any holes in bin, plastic covers, bags, or wrapped bails as soon as possible
3. Discard obviously spoiled feed or layers of feed.
4. Evenly cool grain in the bin during a mild winter- Coring takes one or more truckloads of corn from the bin and levels the crop that remains. This process removes the fine materials that settle in between and fills air pockets between kernels.
5. Clean out leftover feed from feeding bunks regularly.
6. Ensure sufficient and consistent air movement in the bin.
7. When confronted with a toxicity problem, stop feeding the contaminated feed.
8. In consultation with your veterinarian or nutritionist, consider the use of a mycotoxin adsorbent to be mixed with the feed. A modified yeast cell wall extract that is a natural fiber source can often be used at practical levels of inclusion.
Editor’s Note: This commentary is sponsored by Alltech. Mycotoxins are a leading area of study at Alltech. Through 31 years of research-driven product development, Alltech has created a range of natural solutions for the feed and food industries. For more information, please visit the websites at www.alltech.com or www.knowmycotoxins.com.
This commentary is for informational purposes only. The opinions and comments expressed herein represent the opinions of the author--they do not necessarily reflect the opinion of Farms.com. This commentary is not intended to provide individual advice to anyone. Farms.com will not be liable for any errors or omissions in the information, or for any damages or losses in any way related to this commentary.