Moldy hay poses a risk to horses, cattle and people. Here’s what you need to know.
A few years ago, we had a very wet summer. Among the positives were that the pastures grew wildly, and the hay fields were lush with new grass to cut. The biggest negative, as you might guess, was that our cut hay often got rained on or we had to bale it before it was sufficiently dry because more rain was on the way. The result? Moldy hay.
We didn’t have much choice but to gamble and feed the moldy hay, but we tried to manage around it where we could by diluting it with good hay as much as possible. However, we paid a price for that decision with multiple abortions that winter.
I recently read an article featured in Bruce Anderson’s Hay & Forage Minute that got me thinking about this topic. Although we have lucked out with timely rains and drier summers the past couple of years, we still get a random abortion here and there, and it begs the question about whether the hay caused the problem.
Anderson, who is a University of Nebraska Extension forage specialist, writes, “Moldy hay. No matter how hard you try, eventually you have mold in some of your hay and need to decide about feeding it. Feeding moldy hay to livestock is a tough decision. Although all hay contains some mold, when mold becomes easily noticeable, the decisions become important.
“Usually, mold makes hay less palatable, which can result in lower intake or even in animals refusing to eat the hay. Many other problems from mold occur because of mycotoxins produced by certain mold fungi. This also is part of the decision problem since not all molds produce mycotoxins, and the amount produced by those that do is unpredictable.”
I rounded up three direct negative effects of moldy hay from Anderson’s article.
Here are the risks of feeding moldy hay to livestock:
1. Horses are impacted the most by moldy hay and can lead to respiratory and digestive problems like colic or heaves.
2. Cattle aren’t as sensitive to moldy hay, but certain molds can result in mycotic abortions or aspergillosis.
3. Moldy hay also puts ranchers at risk. Mold spores can cause “farmer’s lung,” which results in the fungus growing in the lung tissue if it has been inhaled.
Anderson recommends that feeding moldy hay should be minimized as much as possible to the more sensitive animals like horses and pregnant cows.
“Mold is a difficult problem to deal with. Common sense and good observation often are your best decision aids,” he concludes.
Have you ever had issues with moldy hay? What do you do with your forage if you have discovered a mold issue? Share your thoughts in the comments section below.
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