03/07/2025
Part 2
👨🌾🚜🐴🌷🌼Lets talk about hay, specifically tall fescue and how it can affect equine pregnancy!
Feeding pregnant mares tall fescue that’s infected with an endophytic fungus (Neotyphodium/Epichloë coenophiala) can indeed lead to fescue toxicosis, which in late-gestation mares may cause:
-Prolonged gestation, difficult birth (dystocia), retained or thickened placenta
- **Reduced or no milk production (agalactia)**
-Abortions, stillbirths, or weak/dysmature foals
This is because infected tall fescue produces ergot alkaloids, especially ergovaline, which disrupts prolactin and blood vessel function .
🐴 What’s the risk in Pennsylvania? (I live in PA so i looked specifically into my state)
-Pa is not in the main “fescue belt”, but infected tall fescue (often Kentucky 31) is still found in PA pastures .
-Ergovaline levels in PA fluctuate seasonally: peak in late spring/early summer and again in fall; lowest in winter .
-Even outside the high-risk regions, fescue toxicosis is possible in late-gestation broodmares anywhere that infected fescue grows.
🌿Can feeding pregnant mares tall fescue in Pennsylvania cause them to abort the foal?
-Yes. If the tall fescue is endophyte-infected, it can lead to abortions or stillbirths, along with other severe reproductive issues .
✅ What you can do:
1. Test your pastures/hay to determine:
-% of tall fescue in the stand
-% of those plants infected with endophyte
-Ergovaline concentration (ppb)
(A few places that test, Penn State Extension–Approved Testing Labs, Cumberland Valley Analytical Services (CVAS), Lancaster DHIA Forage Analysis Lab)
2. Management options:
-Remove broodmares from infected pastures 60–90 days before expected foaling (some sources say 45 days minimum)
-Use domperidone in late gestation to prevent toxicosis (prescribed by vet)
-Pasture renovation or overseeding with endophyte-free/novel fescue, orchardgrass, etc.
-Mow before seed heads form to reduce ergovaline levels