07/28/2025
🌧️ Rained-on hay ≠ Moldy hay 🐴
Not all hay that gets rained on prior to baling turns moldy—and not all dry-looking hay is safe. Mold can form in any hay if the conditions are right. Here's what really matters:
💦 Moisture at baling is the biggest factor.
▪️Hay baled at 10–15% moisture = low risk of molding
▪️Hay baled at over 17% moisture without preservative = high risk
🏠 Storage matters too. Even perfectly baled hay can mold if it's:
▪️Stored directly on the ground
▪️Exposed to roof leaks
▪️Left outside unprotected
▪️Exposed to very high humidity for long periods
⏰ Drying time in the field can also play a role.
While less common, prolonged drying time due to high humidity may lead to mold growth before baling.
✅ Bottom line: Rain may complicate harvest but it does not guarantee mold. The real threats to hay, regardless of rainfall, are baling too wet or improper storage.
🚫 Never feed moldy hay to horses.
Even with the best management practices, an occasional moldy bale can still occur. Why? Because conditions within a single field aren't uniform. One bad bale does not mean your whole supply is bad. It's always good to inspect any feedstuffs for mold, pests, or other contaminants prior to feeding.
Learn more about moldy hay ⬇
https://extension.umn.edu/horse-nutrition/dont-feed-your-horse-moldy-hay
