Tall Fescue
Latin Name: Schedonorus arundinaceus; also, Festuca arundanacea
Identifying Characteristics:
- Bunch-type cool-season grass
- Membranous ligule
- Young seedhead appears to be spikelike, but it is a panicle
- Distinct veins on leaf blade
- No obvious midrib on upper leaf surface
- Thick leaf blade as compared to most grasses
- Extremely small serrations on leaf blade edge cause a rough feel
Plant Longevity:
- Perennial
Where Commonly Found:
- Pastures
- Hay fields
- Roadsides
- Waste areas
Time of Most Concern:
- Late spring and summer months, especially in pure stands and when receiving high rates of nitrogen
Compound that Causes Concern:
- Ergovaline alkaloids produced by an endophytic (within plant) fungus (Acremonium coenophialium) are primary responsible for toxicity syndromes
- Alkaloids cause constricted blood flow that limits ability to regulate body temperature
Part of Plant Most Toxic:
- Seed, stem, and leaf sheath
Livestock Species Affected:
- Horses and other equine
- Cattle
- Sheep, to a lesser degree
Pasture, Stored Feed, Both:
- Both
Clinical Signs:
- Lameness (fescue foot)
- Fever
- Non-shedding hair coat
- Decreased weight gain
- Reduced conception
- Reduced milk production
- Longer gestation time with equine
- Standing in water because of fever
- Rapid breathing
- Heat and cold stress
Amount Needed to be Consumed for Clinical Signs / Death:
- Dependent on concentration of ergovaline alkaloids
- Important Note:
- Low-endophyte and novel (friendly) endophyte varieties are not a fescue toxicosis risk
- Concentration of ergovaline alkaloids varies throughout the year; greater concern when seedheads are consumed and lesser concern when stockpiled
- Inclusion of red clover, reduces blood vessel constriction
Identifying Characteristics:
- Bunch-type cool-season grass
- Membranous ligule
- Young seedhead appears to be spikelike, but it is a panicle
- Distinct veins on leaf blade
- No obvious midrib on upper leaf surface
- Thick leaf blade as compared to most grasses
- Extremely small serrations on leaf blade edge cause a rough feel
Plant Longevity:
- Perennial
Where Commonly Found:
- Pastures
- Hay fields
- Roadsides
- Waste areas
Time of Most Concern:
- Late spring and summer months, especially in pure stands and when receiving high rates of nitrogen
Compound that Causes Concern:
- Ergovaline alkaloids produced by an endophytic (within plant) fungus (Acremonium coenophialium) are primary responsible for toxicity syndromes
- Alkaloids cause constricted blood flow that limits ability to regulate body temperature
Part of Plant Most Toxic:
- Seed, stem, and leaf sheath
Livestock Species Affected:
- Horses and other equine
- Cattle
- Sheep, to a lesser degree
Pasture, Stored Feed, Both:
- Both
Clinical Signs:
- Lameness (fescue foot)
- Fever
- Non-shedding hair coat
- Decreased weight gain
- Reduced conception
- Reduced milk production
- Longer gestation time with equine
- Standing in water because of fever
- Rapid breathing
- Heat and cold stress
Amount Needed to be Consumed for Clinical Signs / Death:
- Dependent on concentration of ergovaline alkaloids
- Important Note:
- Low-endophyte and novel (friendly) endophyte varieties are not a fescue toxicosis risk
- Concentration of ergovaline alkaloids varies throughout the year; greater concern when seedheads are consumed and lesser concern when stockpiled
- Inclusion of red clover, reduces blood vessel constriction