Dallisgrass
Latin Name: Paspalum dilatatum
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
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
Reddy et al. Tremorgenic Mycotoxins: Structure Diversity and Biological Activity. Toxins. 11(5), 302. 2019