Poisonous Pasture Weeds

Plant

Problems/symptoms

Toxic ingredient — toxicity dosage

Bouncing bet

Leaves and stem – delayed for several days; depression, vomiting, abdominal pain, diarrhea

Saponin – amount equivalent to 3% animal dry weight) will kill within 4 hrs.

Buttercups

Leaves and stem especially in flower. Dried hay loses toxicity - anorexia, salivation, weakness, convulsions, breathing difficulty, death

Protoanemonin - toxicity reported to vary with species, age, and habitat, Generally 1-3% of body weight necessary.

Cherry, black

Leaves (wilted leaves are worse), stems, bark and fruit - anxiety, staggering, breathing difficulty, dilated pupils, bloat, death

Cyanogenic glycosides - Less than 0.25 lb leaves (fresh wt.) can be toxic to 100 lb animal. Leaves from several small to mid-sized branches are sufficient to kill an adult animal.

Hemlock, poison

All plant parts - nervousness, salivation, vomiting, diarrhea, weakness, paralysis, trembling, dilation of pupils convulsions, and coma, death

Coniine and others (pyridine alkaloids) - 0.5 to 4% (fresh wt,) equivalent of cattle wt, is toxic. In horses, 0.25% of body weight.

Jimsonweed

Entire plant (seeds are most toxic) - Thirst, mood swings, convulsions, coma, death

Solanaceous alkaloids – 0.06 to 0.09% (dry wt.) equivalent of animal body wt, is toxic.

Locust, black

Leaves (especially wilted), seeds, and inner bark - causes weakness, depression, anorexia, vomiting and diarrhea

Phytotoxin robin, glycoside robitinm - bark extract and powder in amount equivalent to 0.04 - 0.1% of animal wt. toxic to horses, Cattle 10-times more tolerant.

Milkweeds

Entire plant - depression, muscle tremors, spasms, bloat, difficult breathing

Glycosides and galitoxin - 0.3 to 0.6% of body weight.

Nightshade species

Vegetation, unripe fruit - loss of appetite, salivation, weakness, trembling, paralysis

Solanine - toxic at 42 mg/kg (LD₅₀). 0.1 to 0.3% of body weight.

Pigweed species

Foliage (worse in drought) - kidney disease, weakness, edema, rapid respiration

Nitrates nitrate oxalates, unknown - 0.5 to 1% of diet. Sheep, hogs, and young calves most susceptible.

Pokeweed

Entire plant, especially roots – gastrointestinal cramps, weakened pulse, respiration, salivation

Phytolacctinm - 10 or more berries can result in toxicity to humans, Unknown for livestock, but perhaps 100-200 berries/1000 lb.

Snakeroot, white

Leaves and stem - constipation, loss of appetite, salivation, rapid respiration. Toxin passes through milk (milksickness)

Trophine alkaloid - varies from 1 to 2% of animal body wt, after 2 weeks. Toxin cumulative.

St. Johnswort

Flowers and leaves – photosensitivity which leads to redness of muzzle, around eyes, and around white hair

Hypercin - uncertain