Reed canarygrass suspected in cattle deaths
Apr 23, 2009 9:21 AM
The West Virginia Department of Agriculture (WVDA) is investigating the death of approximately 20 head of cattle in the southern part of the state, and the current prime suspect is toxin contained in reed canarygrass.
“We have ruled out any infectious diseases,” said Commissioner of Agriculture Gus R. Douglass. “Although we are not positive canarygrass is to blame, we want to alert producers and ask them to report any unusual deaths in their herds to their local veterinarian.” The telltale symptom in these deaths is partial paralysis of rear limbs, according to State Veterinarian Dr. Gary Kinder, although some animals died suddenly without obvious symptoms.
Animal age, nutrition and general health may also be factors, he noted. Producers who note these symptoms in their cattle or sheep herds should contact their veterinarian.
Veterinarians with questions may contact WVDA’s Animal Health Division at 304-558-2214. Post-mortem testing performed at Virginia Tech University as part of WVDA’s investigation indicates the animals died from poisoning from reed canarygrass. Although it is a hardy, common species found worldwide — and generally not considered problematic for livestock — potentially dangerous levels of alkaloid toxins can accumulate in the grass during drought conditions and during regrowth after grazing or mowing.
There currently is no way to test for the toxin levels in feed or grass, and Dr. Kinder advised farmers to exclude animals from stands of canarygrass, which tends to grow best in damp areas.
Information on identifying reed canarygrass is available here, or by calling WVDA’s Plant Industries Division at 304-558-2212.
Dr. Kinder also said producers should increase the cobalt concentration in free choice mineral supplements to approximately 250 ppm. Cobalt will not reverse symptoms in affected animals, but is thought to help prevent absorption of the toxins.
Sheep are also susceptible to reed canarygrass poisoning, and there is no known treatment once animals become symptomatic. WVDA is continuing its investigation in cooperation with Virginia Tech, West Virginia University and the U.S. Department of Agriculture.
DESCRIPTION: Reed canarygrass is a cool-season grass that grows 3-8 feet tall. It forms dense, monospecific stands in wet meadows, riparian areas, and marshes; spreading by means of stout rhizomes. Established plants of reed canarygrass can tolerate prolonged periods of inundation. Other species that might be confused with reed canarygrass include: common reed (Phragmites australis), Canada bluejoint (Calamagrostis canadensis), or orchard grass (Dactylis glomerata).
The long, membranous ligule of reed canarygrass can be helpful in distinguishing it from the others. In addition, unlike common reed, the stems of reed canarygrass do not remain standing through the winter.
Height: Flowering stems grow from 3-7 feet tall.
Stem: The stem is smooth, green, and erect.
Leaves: Leaves are 4-8 inches long and about ½ -inch wide; the ligule is unusually large – up to ½ inch long.
Flowers: Flowering occurs in June and July.
Fruit and seed: The 3-10 inch long branched inflorescence is at the top of an erect stem. It is green with a purplish tinge; although narrow at first, it opens up when in flower. The plume contracts and becomes light tan in color in the fruiting stage. Seeds germinate most readily immediately after they mature.
Roots: Reed canarygrass spreads by rhizomes to form large clonal colonies
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