Is Fescue the Right Choice for Your Horse Pasture?

This time of year, calls start coming in on pasture management.  What to grow, when to plant, how and when to fertilize, control weeds, etc.  One of the common questions I have experienced this year has been specific to fescue, and whether or not it is a good grazing choice or a concern in pastures.  There are many things to consider if fescue is part of your established pasture or a possible choice for a future pasture. 

Tall Fescue is a very widely used forage, often said the most commonly found pasture grass across the United States.  Fescue is a cool season perennial grass, and even though it is one of the oldest, most commonly found grasses, it has experience many changes and improvements throughout recent years.   Much of the discussion and literature you will find about fescue is regarding an “endophyte” fungus that often comes with the plant.  The word endophyte means that the fungus grows inside the plant, instead of growing on outer portions of the plant as with many other fungi.  The endophyte most often of concern with fescue is Acremnium coenophialum or more recently known as Neotyphoidium coenophialum, and it can only be detected by laboratory analysis.   The problem we often discuss with considering fescue is that the fungus can have an adverse affect on animals grazing the forage, while it does not harm the plant.  Actually, the endophyte is good for the plant, because it helps the grass be more tolerant to close grazing, drought, and pests.  Infected fescue has better seed germination rates, improved tillering, and is more competitive with other plant species than non-infected fescue.    

Preventing Problems with Horses Grazing Fescue: 

Fungus infected fescue is known to cause many problems in grazing animals, specifically referred to as “fescue toxicity”.  For horses in particular, there are many concerns, mostly with regard to broodmares.  Some of the adverse affects of broodmares grazing fescue include abortions, prolonged gestation, dystocia (difficult birth), thick or retained placentas, agalactia (poor milk production), and in worst cases foal or mare death from foaling complications.  Research regarding fescue and a complication from the endophyte fungus began in the 70s and has progressed throughout many land grant universities, revealing similar results.  The overall consensus when managing broodmares is to determine  if endophyte infected fescue is in the pasture and replace this fescue with an alternative, non-infected grass. There are low or non-infected fescue varieties and “endophyte friendly” or “novel” varieties available that are safe for feeding the mare, which contain an edophyte that is non-toxic to the animal but also provide the same benefits to the plant as the toxic endophyte fungus.   The other obvious and sometimes quicker solution is to make sure pregnant mares do not graze these fescue pastures.  Horses in particular (over other livestock species) tend to be extremely sensitive to the endophyte.  Recent studies have indicated that removing the pregnant mare 30-45 days prior to foaling will greatly reduce problems with foaling and lactation, while initial research recommended removal for 90 days prior to foaling.  In the event that a mare must remain on a fescue pasture, research has shown that she can be treated with a daily oral dose of the drug domperidome for 10-15 days prior to foaling.  Treatment can also be conducted after foaling to assist with milk production if preventative treatment wasn’t offered. Be sure to contact your veterinarian for guidance and advice on treating mares with domperidome.

How do I know if I have infected fescue?

If your pasture is primarily fescue grass and you want to determine what percent is infected, sampling is the best method.  Samples of plant stems should be taken randomly throughout the field, and sent for laboratory analysis.  The NC Department of Agriculture offers a fescue endophyte testing service for fescue grass or seed.  Grass samples in NC are $15, while seed is $15 or $25 depending on the seed crop.  For specific instructions on how to take and send a sample for analysis, horse owners should either contact their local NC Cooperative Extension office or contact the NCDA at 919-733-3930 or visit the website: http://www.ncagr.gov/plantindustry/seedandfertilizer/seed/Endophyte.htm .  A descriptive brochure is available with details on sampling and submission of the sample.  Once you have determined what percent of the pasture is infected, steps can be taken to remove or replace the infected fescue with more desirable forages, depending on the situation.

I hope this has helped explain the concerns with horses and other equines grazing fescue, and how to prevent or solve associated problems.  For additional assistance, contact your local county Extension Center.