LOVELOCK - Halogeton is an annual weed that is poisonous to sheep and cattle. It was first observed in the United States near Wells, Nev., in 1934.
Cattle and sheep are susceptible to intoxication and death from consumption of halogeton, but cases of large scale poisoning of cattle are rare compared to sheep.
Most losses occur when hungry and thirsty animals are allowed to consume large amounts of halogeton. The toxic substance in halogeton is sodium oxalate, which is contained in leaves and other above ground parts of the plant. Halogeton is dangerous at all times. However, it becomes more toxic as the growing season advances, reaching a peak of toxicity at maturity.
Halogeton is actually more toxic to cattle than sheep, but because of the free roaming behavior of cattle they seldom consume enough to become intoxicated.
Symptoms of toxic consumption of halogeton on winter ranges are cattle become stiff and walk with extreme difficulty when driven. Some cattle lay down and stay down for several days.
In 1962, ranchers in Elko County lost about 150 cows in one day to halogeton poisoning.
The cows were driven down an old sheep trail where there were moderate to high concentrations of halogeton. The presence of frost on the halogeton probably contributed to the consumption of the toxic weed by thirsty cattle.
Sheep can tolerate large amounts of halogeton if they eat other forage at the same time and if they have been acclimated to halogeton in their diet. About 12 ounces of halogeton dry matter will kill a sheep that has been without feed for a day or longer.
What can ranchers do to prevent accidental poisoning of their livestock?
Halogeton often grows along railroad beds, roads, trails, and in other places where the soil has been disturbed. Dense stands are found on burned-over areas, overgrazed ranges, dry lakebeds, and abandoned dry farms.
Halogeton, however, lacks the capacity to compete with vigorous perennial plants and the more aggressive annuals.
Livestock losses may be reduced by maintaining range that supports good forage and by proper management of animals on halogeton-infested ranges.
Supplemental feeding helps prevent halogeton poisoning when animals trail through or graze infested areas. Animals unloaded in halogeton-infested areas after shipment may benefit from supplemental feeding before grazing in the halogeton-infested areas.
Livestock should not be placed into areas heavily infested with halogeton unless they can be introduced slowly to allow time for adaptation to the toxin. Always allow animals access to water.
Livestock should not be allowed to become hungry or thirsty while grazing in areas infested with halogeton. Death in livestock occurs when an animal eats a large amount of halogeton in a short period of time.
Treatments for halogeton poisoning have not been definitely proven to be effective. It has been suggested that oral dicalcium phosphate may reduce oxalate bioavailability by forming insoluble calcium oxalates (3:1 salt to dicalcium phosphate or 5 percent calcium phosphate in alfalfa pellets).
Treatment of hypocalcemia with intravenous calcium gluconate will correct the hypocalcemia, but does not reverse the clinical signs or course of the disease.
Plants can be held in control by proper use of herbicides (2.4-D LV ester, Plateau and Escort), and small infestations can be eradicated if treated early.
Revegetating infested rangelands with more desirable species of perennial grasses seems to be the most economical and practical method of controlling the spread of halogeton. Repeated treatments are necessary for control. Seeding infested areas with crested wheatgrass has been used extensively to crowd out halogeton and improve ranges.
Source:"Halogeton poisoning," Ron Torell, Dr. James A. Young, Dr. Bill Kvasnicka.[[In-content Ad]]
