Dallisgrass

Identifying Characteristics:

• Spreads by rhizomes, but grows in clumps
• Greyish green color
• Seed is located on the sides of numerous seedhead stalks
• Similar appearance to crabgrass, but seedhead stalks and seed are larger

Plant Longevity:

• Perennial warm-season grass

Where Commonly Found:

• Pastures
• Hay fields
• Roadsides
• Ditch banks

Time of Most Concern:

• Late summer when seed heads are present
• Humid conditions needed for development of ergot fungus

Compound that Causes Concern:

• Ergot fungus, Claviceps paspali, produces the toxins paspalinine and two tremor-causing alkaloids paspalitrem A and B

Part of Plant Most Toxic:

• Seed

Livestock Species Affected:

• Cattle
• Sheep
• Horses
• Goats

Pasture, Stored Feed, Both:

• Both

Clinical Signs:

• "Dallisgrass staggers"
  • Uncontrolled twitching
  • Sudden movements
  • Easily spooked
  • Swaying, incoordination, acting "drunk"
• Diarrhea
• Inability to stand
• Distrust in people

Amount Needed to be Consumed for Clinical Signs / Death:

• Rations containing more than 0.6% alkaloids are potentially toxic
• Paspalinine toxicity is 8 mg compound / kg of body weight in mice
  • This translates to about 0.13 ounces for a 1000 lb cow
• Paspalitrem toxicity is 14 mg compound / kg body weight in mice
  • This translates to about 0.22 ounces for a 1000 lb cow
• No published studies in ruminants