TexasAgriculturalExtensionServiceThe Texas A&M University System

Reducing LivestockLosses to Toxic Plants

B-1499

Sand Shinnery

L

Perennial Broomweed

Texas Agricultural Extension Service ● Zerle L. Carpenter, Director ● The Texas A&M University System ● College Station, Texas

TableofContentsDiagnosis............. ............................... 3GrazingManagement................................... 3SupplementalFeeding.................................. 4Plant Control ................... ................ 6BehaviorModification.................................. 7Management Techniques forReducingToxic Plant Losses... 8LiteratureCited........................................ 9Poisonous Plants ofTexas...............................10

Editor: Judy Winn,Extension CommunicationsSpecialistTheTexasA&MUniversitySystem.

Cover design byRhondaKappler, ExtensionCommercial Artist

Reducing Livestock Lossesto Toxic Plants

Allan McGinty and Rick Machen*

More than 100 species of toxic plants in-fest Texas rangelands. These plants affectranch businesses directly by causing live-stock death. They also have such indirect ef-fects as lower conception rates and weaningweights, increased supplemental feedingcosts and reduced production of desirablerange forage. One toxic plant, perennialbroomweed, is estimated to cause more than$30 million in indirect and direct losses peryear in Texas (McGinty and Welch, 1987).

Diagnosis

Some toxic plants produce easily identifi-able symptoms. For example, sacahuistacauses photosensitization (hyper-reaction tosunlight), which results in obvious inflam-mation, swelling and sloughing of the skin.But accurate diagnosis of poisonous plantproblems can be difficult. Chronic poisoningfrom perennial broomweed usually causesabortion, which may be mistakenly blamedon improper management practices or dis-ease. Many cases of livestock poisoning aremisdiagnosed and millions of dollarswasted with improper treatment.

The time frame over which symptomsoccur adds to the difficulty of diagnosis.Plants which produce toxic amounts of prus-sic acid (i.e., sorghum species) can killanimals within 15 minutes. On the otherhand, threadleaf groundsel may not produceclinical signs or death for 9 to 12 monthsafter consumption.

When a sick or dead animal is found, thefirst step in diagnosis is to determine

*Extension range specialist and Extension livestock-specialist, The Texas A&M University System.

whether the cause is plant poisoning or in-fectious disease. To do so it is necessary tocarefully observe symptoms exhibited by af-fected animals and to have a thoroughknowledge of plants native to the area.

Assuming a poisonous plant is respon-sible, the next step is to identify the plant.Again, symptoms are important when nar-rowing the suspected plant to one or a fewspecies. It is also helpful to observe whetherany toxic plant species within the pasturehave been grazed. Finally, the rumen of adead animal can be opened and a sample ob-tained of the ingested forage. Careful ex-amination of the rumen contents can assistin identifying the toxic plant responsible.

If death has been recent, a post-mortemexamination may reveal clues to the cause.For example, threadleaf groundsel poisoningproduces a hard, yellow liver, while nitratepoisoning is often identified by chocolate-brown colored blood present for 2 to 4 hoursafter death. If a layman attempts to performthe autopsy, he should take adequatesanitary precautions to prevent self-infec-tion in the event the animal died from infec-tious disease.

Correct diagnosis of a poisonous plantdeath is often a difficult, time-consumingprocess. Assistance is available from localveterinarians, the Texas Agricultural Exten-sion Service, the Soil Conservation Serviceor the Texas Veterinary DiagnosticLaboratory.

Grazing Management

Animals grazing rangelands are often ex-posed to a wide variety of potentially

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“...grazing manage-ment...can be im-portant in reducinganimal losses totoxic plants.”

poisonous plants. Because of this, re-searchers and ranchers have long recog-nized that grazing management, “themanipulation of livestock to obtain a desiredresult,” can be important in reducing animalroses to toxic plants. This manipulation oflivestock involves decisions about the stock-ingrate and grazing system used and thespecies of livestock grazed.

Stocking Rate

A rancher’s most important managementdecision is the maintenance of appropriatelivestock stocking rates, which involves bothhe initial setting of rates and subsequentseasonal adjustments. Stocking ratedecisions affect not only individual animalperformance (i. e., weaning weights and con-ception rates) but also livestock consump-tion of toxic plants.

When stocking rates are excessive, rangecondition declines. The production anddiversity of desirable plants is suppressedwhile toxic plants become more numerous.As a result, the probability that livestockwill consume toxic plants increases.

Grazing Systems

Because livestock are selective grazers,they often excessively graze the plants theyprefer. Over time these preferred plants maydecline or disappear from the range. Graz-ing systems which allow rangeland to restperiodically promote the regrowth ofpreferred plants and reduce poisonous plantproblems. Research conducted at the SonoraExperiment Station compared toxic plantdeaths in the Merrill three-herd, four-pas-ture deferred rotation grazing system withthose under continuous grazing. The Merrillsystem reduced livestock losses to bitterweed,oaks and sacahuista over a 20-year period(Taylor, 1990).

Intensive grazing systems (in which in-dividual pastures are grazed intensively forshort, infrequent periods) provide flexibilityin livestock movement that can reduce toxicplant problems. For example, it maybe pos-

sible to increase livestock numbers within aproblem pasture to a point at which in-dividual animals cannot obtain a toxic quan-tity of a poisonous plant (Ralphs andSharps, 1988). Also, if intensive grazing sys-tems use a large number of pastures, it iseasier to avoid pastures with known his-tories of poisonous plant problems duringcritical times of the year.

Rotation timing is critical in intensivegrazing systems because livestock densityusually greatly exceeds the annual carryingcapacity of individual pastures. If livestockare left too long in a pasture they will con-sume all desirable forage and are then morelikely to consume the normally unpalatabletoxic plants. Depending on the intensity ofthe system, this series of events may occur inonly a matter of days.

The type of grazing system used is not asimportant as adhering to the principles ofgood grazing management. Years of re-search have shown that regardless of thegrazing system used, excessive stockingrates cause range condition to deteriorateand toxic plants to proliferate

Livestock Species Grazed

Livestock species differ in both their graz-ing behavior and susceptibility to toxicplants. These differences can be managed toreduce toxic plant losses. For example, re-searchers at the Sonora Experiment Stationhave proved that there are fewer livestocklosses to western bitterweed when a combina-tion of cattle, sheep and goats is grazed thanwhen a single species is grazed (Merrill andSchuster, 1978). A second example is Woollypaperflower, a palatable plant in the Trans-Pecos region of Texas that is toxic to sheepbut not to cattle. Because of this difference insusceptibility, cattle can be grazed ahead ofsheep to reduce the quantity of woollypaperflower available for sheep consumption.

Supplemental Feeding

Deficiencies in protein, energy, mineralsor vitamins may increase the probability

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that livestock will ingest toxic plants. Thesedeficiencies can be corrected with sup-plemental feeding programs.

When to Supplement?

Generally, supplemental feeding is mostimportant during the winter and earlyspring when forage quality is fair to poorand most livestock have their highestnutrient requirements (last one-third of ges-tation and lactation). Livestock body condi-tion and forage testing can help definenutrient-deficient periods.

With What to Supplement?

Minerals must receive high priority in anysupplementation program. For example,phosphorous is considered the most limitingnutrient in most Texas forages. In fact, whenrainfall is below normal, forage phosphoruscontent may never meet basic livestockmaintenance requirements. Phosphorousdeficiency causes abnormal grazing be-haviors or cravings, which make livestockmuch more likely to consume normally un-palatable toxic plants. Other minerals whichmay be deficient on Texas rangelands in-clude potassium, copper, magnesium,sodium, iron and zinc.

Some forages, particularly in west Texas,have a calcium content that greatly exceedsthe phosphorous level within the plant. Inthese cases, mineral supplements shouldcontain no more than one part calcium foreach part phosphorous (1:1 ratio). Feedingan “inverted” mineral (1:2 calcium: phos-phorous ratio) may also be beneficial.Regardless of the calcium: phosphorous ratioor nutrient source, phosphorous supplemen-tation tends to reduce the probability oftoxic plant consumption.

The second most limiting nutrient isprotein. Forages are usually protein-defi-cient from first frost until spring green-up.Should winter moisture be available, coolseason grasses and forbs may alleviateprotein deficiencies to some extent. Unfor-tunately, toxic plants such as woolly 1oCOare

also green and relatively high in proteinduring wet winters and may be preferred bylivestock. Therefore, supplementation mustcorrect any protein deficiencies in order tominimize toxic plant consumption. Resultsof Experiment Station studies indicate thatthe form of the protein supplement is alsoimportant. To reduce toxic plant consump-tion, natural proteins (such as oilseed meals)should be used. Nonprotein nitrogen supplements (urea) may aggravate rather than al-leviate toxic plant problems.

Vitamin A deficiency may also increaseconsumption of toxic plants. Vitamin A canbe stored by the grazing animal for up to 90days. If no green forage is available for thatlength of time, it is generally recommendedthat Vitamin Abe supplemented.

How Much to Supplement?

The quantity of supplement to provide isperhaps the most difficult decision. If toomuch supplement is provided profitabilitysuffers. If not enough is provided individualanimal performance suffers. The correctamount depends upon:

● nutrient content of the supplement

● livestock body condition

• physiological status of the livestock

● forage quantity

● forage quality

. weather conditions

Because livestock eat little mineral supple-men t it is difficult to monitor consumption.Consumption fluctuates throughout theyear, but as a “rule of thumb” a cow shouldingest an average of 0.2 pound of mineralsupplement per day, a sheep or goat about0.05 pound per day.

Supplementation cannot completelyprevent toxic plant consumption. However,ranchers can reduce their losses by provid-ing proper quantities of needed nutrients atcritical times.

“Ranchers canreduce their lossesby providing properquantities ofneedednutrients at criticaltimes.”

I Plant Control

It is often necessary to control poisonousplants on rangeland. Control may takemany forms and be practiced to variousdegrees. An effective program will reduceor prevent livestock losses and be cost effec-tive.

What Toxic Plants Should be

IControlled?

Determining which plant species to targetrequires considerable thought and planning.Species such as lechuguilla and sacahuista areresistant to most control practices, whileothers such as whitebrush may not be worthcontrolling because they pose only a slightthreat to livestock. These plants ma y bemore effectively managed by selecting ap-propriate livestock species, grazing systemsand supplemental feeding programs.

In other cases, the first presence of a toxicplant should trigger control efforts. This isespecially true for plants such as African rue,a highly toxic species which spreads quicklyalong ranch roads and is resistant to all butthe highest, most expensive rates of her-bicides (Sperry et al., 1968).

A rancher must know a poisonous plant’slevel of toxicity, its ability to spread acrosspastures and its susceptibility to control

“Toxic plants pose methods. With this information, sound

variable levels of decisions can be made concerning which

risk, depending on toxic plant species should be controlled.

where they grow.”Where Should Toxic Plants beControlled?

Toxic plants pose variable levels of risk,depending on where they grow. Livestockhandling facilities and bedding/feedinglocations are high risk areas. In these sitesthe soil is continually disturbed, whichpromotes the invasion of toxic plants. Andbecause livestock spend considerable timein these areas, they are more likely to eatany poisonous species which grow there.

Ranch roads are another high risk area.Toxic plants such as African rue, western bit-terweed and twinleaf senna enter the ranch asseeds on the tires and frames of vehicles andgerminate along road sides. To prevent theirspread into adjacent pastures, these plantsshould be controlled when they first appear.

Although many toxic plant speciesremain in localized areas, others such asperennial broomweed and woollylocoweed maydensely infest entire pastures. In these situa-tions it is necessary to broadcast herbicides,a Ithough efforts must be made to keep theapplications cost effective. For example,perennial broomweed could be treated only inpastures used by pregnant livestock. Thiswould minimize costs while reducing oreliminating the abortions caused by peren-nial broomweed.

When Should Toxic Plants beControlled?

The “when” of toxic plant control mayhave both long- and short-term conno-tations. Most control practices are more ef-fective when applied at a specific time of theyear. Such seasonal timing will vary greatlydepending on the plant species involvedand control practice or herbicide used. Fordetailed information on the seasonal timingof herbicide applications refer to Extensionbulletin B-1466, “Chemical Weed and BrushControl - Suggestions for Rangeland”(Welch, 1990), available from your countyExtension agent.

Over the long term, the best time to con-trol a poisonous plant is before it increasesin range and density. High risk areas shouldbe constantly monitored and toxic plantstreated as soon as they appear. The oldsaying “an ounce of prevention is worth apound of cure” applies to toxic plantmanagement.

How Should Toxic Plants beControlled?

A variety of plant control options is avail-able. These include fire as well as mechani-

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cal, biological and chemical methods. Fire isa proven tool for manipulating vegetation.Unfortunately, it rarely kills plants andtherefore is of limited use in toxic plant con-trol. In west Texas fire may not be effectivebecause of low fuel loads and poor fuel con-tinuity.

Mechanical methods such as chaining,railing, rootplowing or grubbing will con-trol woody toxic plants such as whitebrush ormesquite, but the soil disturbance these prac-tices cause may promote the establishmentof herbaceous toxic plants such as western bit-terweed, twin leaf senna or African rue. Shred-ding or mowing can be somewhat useful inthe control of herbaceous, annual toxicplants, although terrain and woody plantcover usually prohibit their use. Hand pull-ing or grubbing, while certainly not the ap-propriate method once plants are denselyestablished, has kept many ranches free oftoxic plants for decades.

Biological control may be the hope of thefuture. A moth borer has been used success-fully to control prickly pear cactus inAustralia. St. Johnswort, a poisonous rangeweed in the western United States, is control-led by leaf-eating beetles (Klingman andAshton, 1975). The Agricultural ResearchService is presently evaluating a weevil forcontrol of perennial broomweed.

In many cases herbicides are the mosteconomical and efficient method of control.When plants densely infest large acreages,commercial aerial application should beused. If the targeted plant is scattered alongthe edges of ranch roads or confined toother localized areas, ground applicationswill be more appropriate.

Ground applications of herbicides can bemade with either broadcast or individualplant treatment techniques. As a generalrule, if plant density exceeds 100 to 200plants per acre, broadcast applications willbe more cost effective.

Broadcast, ground applications do not re-quire a large investment in equipment. By at-taching a clusterjet (boomless) nozzle orspray boom, livestock sprayers can be cheap-ly converted ($100 or less) to apply liquid,

foliar-applied herbicides. When rinsed, thesprayer may still be used to spray livestock,but not to spray desirable shade or fruittrees. There is also spray equipment ($250 to$750) that attaches to 4-wheel motorcycles.

When plants are sparse or erratically dis-tributed, individual plant treatment may berequired. The same stock sprayer used forbroadcast applications can be used for high-volume, foliar spraying. Herbicide is mixedwith water on a volume basis and applied athigh pressure with a hand gun until theplant is uniformly wet. When terrain limitsthe mobility of a stock sprayer, a backpackor small 1- to 3-gallon “pump-up” gardensprayer may be used. Spray equipmentmounted on 4-wheel motorcycles or otheroff-road vehicles may also be fitted withhandguns.

The type of herbicide to use and the rateand season of application can be determinedby referring to Extension publication B-1466,“Chemical Weed and Brush Control Sugges-tions for Rangeland. ”

One special precaution concerns the im-pact herbicide applications have on plantpalatability. Once sprayed plants begin towilt, they are much more likely to be con-sumed by livestock. Thus, livestock shouldnot be grazed on treated areas until theplants are completely desiccated.

Behavior Modification

Researchers at the USDA-ARS PoisonousPlant Lab and Utah State University arediligently working on a practical method ofteaching livestock not to eat toxic plants.This behavior modification process isknown as food aversion learning (Ralphsand Provenza, 1990).

Tall larkspur is the most importantpoisonous plant on Utah mountain ranges,causing persistent losses in cattle of up to 10percent annually. The plant is palatable andacutely toxic. Researchers have successfullytaught several groups of cattle not to eatlarkspur (Lane et al., 1990; Olsen et al., 1989;and Ralphs and Olsen, 1990). Aversion was

“Biological controlmay be the hope ofthe future.”

Management Techniques for Reducing Toxic Plant Losses

● Do not overgraze rangeland. Many poisonous plants are classified as increasers orinvaders, meaning that they become more common on rangeland in poor condition.

● Be cautious when introducing livestock from other geographic locations. They aremore likely to consume toxic plants than are native cattle.

● Do not turn hungry stock onto pastures infested with toxic plants because hungryanimals are much less selective about the plants they eat.

● Make certain livestock have free access to salt and mineral supplements. Nutrientdeficiencies may make animals less selective in their grazing.

● Provide adequate, clean water.

. Do not feed hay that contains poisonous plants.

● Minimize grazing pressure when poisonous plants are the most dangerous. Useflexible grazing systems so that high risk areas can be left ungrazed when thetoxicity hazard is greatest.

● Use the proper kind and class of livestock. One class of livestock is often more resis-tant to a toxic plant than others.

● Be alert when herding livestock through infested areas. Stock should have fullstomachs when trailed or penned. Also, avoid crowding animals.

● Be aware of special environmental conditions that may restrict animal movementor change diet selection. Such conditions include drought, snow or extremely wetconditions.

● Be cautious when grazing areas recently burned or sprayed with herbicide. Thesepractices can increase toxic plant palatability.

● Finally, know the toxic plants that might occur on your ranch and watch forevidence of grazing. When problems are detected early, losses can be minimized.

Literature Cited

Hatch, Stephan L., Kancheepuram N. Gandhi andLarry E. Brown. 1990. “Checklist of the vascular plantsof Texas.” Texas Agricultural Experiment Station, MP-1655.

Klingman, G. C. and F. M. Ashton. 1975. Weed scienceprinciples and practices. John Wiley and Sons: NewYork, N.Y.

Lane, M. A., M. H. Ralphs, J. D. Olsen, F. D. Provenzaand J. A. Pfister. 1990. “Conditioned taste aversion:potentialfor reducing cattle loss to larkspur.” JournalofRangeManagement. 43:127-131.

McGinty, Allan and Tommy G. Welch. 1987. “Peren-nial broomweed and Texas ranching. ”Rangelands.9:246-249.

Merrill, L. B. and J. L. Schuster. 1978. “Grazingmanagement to reduce livestock loss from poisonousplants.”J ournal of Range Management. 31:351-354.

Olsen, J. D., M. H. Ralphs and M. A. Lane. 1989. “Aver-sion to eating poisonous larkspur plants induced incattle by intraruminal infusion with lithium chloride.”Journal of Animal Science. 67:1980-1985.

Ralphs, M. H. and L. A. Sharps. 1988. “Management toreduce livestock loss from poisonous plants.” In: TheEcology andEconomic Impact of Poisonous Plants onLivestock Production. Westview Press: Boulder,Colorado. Intermountain Research Station TechnicalReport INT-222. pp. 391-405.

Ralphs, M. H. and J. D. Olsen. 1990. “Overcoming theinfluence of social facilitation in training cattle toavoid eating larkspur.” Journalof Animal Science.68:1944-1952.

Ralphs, Michael H. and Fred D. Provenza. 1990. “Mini-mizing toxic plant losses through behavior modifica-tion.” In: Proceedings, West Texas Toxic PlantSymposium. Ft. Stockton, Texas. pp. 47-54.

Sperry, O. E., J. W. Dollahite, G. O. Hoffman and B. J.Camp. 1968. “Texas Plants Poisonous to Livestock.”Texas Agricultural Extension Service, B-1028.

Taylor, Jr., Charles A. 1990. “Minimizing toxic plantIosses through grazing management.” In: ProceedingsLWest Texas Toxic Plant Symposium. Ft. Stockton,Texas. pp. 47-54.

Welch, T. G. 1990. “Chemical Weed and Brush ControlSuggestions for Rangeland.” Texas Agricultural Exten-sion Service, B-1466.

Poisonous Plants of Texas

Scientific Common Basic toxic Typical symptoms Remarksname* name principle

Acacia berlandieri Guajillo Three sympatho- Locomotor incoordination Guajillo is a valuable browseminetic amines of the legs plant if managed correctly.

Acacia constricts Whitethorn Hydrocyanic acid See prussic acid poisoning Livestock generally will notgraze whitethorn unlessseverely stressed.

Aesculus spp. Buckeye Glycosides Staggering gait, weakness, Children have been poisonedtrembling, congested mucous by eating the nut-like seed.membranes, dilated pupils

Agave lechuguilla Lechuguilla Saponi n Listlessness and yellow Sheep and goats are mostdischarge from eyes and frequently poisoned.nostrils, urine port wine color;see photosensitization (hepatic)

Allium spp. Wild onion Alkaloids Intense gastroenteritis, urine Large amounts are needed toport wine color, icterus, be toxic.anemia

Aloysia gratissma Whitebrush, Unknown Lack of stamina, emaciation, Only horses, mules and burrosvar. gratissima beebrush lameness, excessive sweating are affected.

Amaranthus spp. Amaranth, Nitrates See nitrate poisoning These plants can be relativelycareless- weed, palatable to livestock.pigweed

Apocynum Dogbane, Resins and Symptoms not well docu- Cases of poisoning are rare.cannabinum indian hemp glycosides mented

Asclepias latifolia Broadleafmilkweed

Glycosides Restlessness, abdominal pain, Young plants are more toxic

Asclepias Horsetail Gsubverticillata milkweed

excessive salivation and than mature plants.labored breathing

ycosides Rapid and weak pulse, This plant is generally notrespiratory paralysis, loss of considered palatable tomuscular control, trembling, livestock; most poisoning isstaggering, violent convulsions from hay.

Asclepias Whorled Glycosides See Assc!epias subverticillata This plant is poisonous at allverticillata milkweed stages of growth.

Astragalus Ravine, emory Misertoxin Collapse of leg muscles when This plant is easily confusedemoryanus loco animal attempts sudden with nontoxic species.

movement, general incoordin-ation of hind legs, laboredbreathing

Astragalus spp. Locoweed Unknown Slow staggering gait, rough Very large amounts arecoat, staring look, emaciation, necessary for poisoning.muscle incoordination

Avena fatua Oat Nitrates See nitrate poisoning andvar. sativa photosensitization

*Scientific namesof plants follow those of1 latch et al. (1990).

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Scientific Common Basic toxic Typical symptoms Remarksname name principle

Baileya Desert baileya Unknown Frothy green salivation, ex- Poisoning under rangemultiradiata treme weakness, rapid heart- conditions is generally

beat, trembling of limbs, limited to sheep.standing with arched backor lying down and refusingto move

Baptisia spp. False indigo, Alkaloids Diarrhea, anorexia Plants are rarely consumedbaptisa except in hay.

Centaurium Mountain pink, Unknown Loss of appetite, abdominal This plant is relativelybeyrichii centaury pain, diarrhea unpalatable.

Centaurium Buckley Unknown Loss of appetite, abdominal This plant is relativelycalycosum centaury, pain, diarrhea unpalatable.

centaury

Cephalanthus Buttonbush Glycosides Symptoms not well docu- Livestock poisoning cases areoccidentals mented rare.

Cestrum diurnum Jessamine, Vitamin D Weight loss, emaciation, Plants must be consumed overcestrum metabolitc lameness, death a period of time.

Cheilanthes Jimmyfern Unknown Stilted, uncoordinated walk, This plant is usually fatal tocochisensis arched back, violent trembling, sheep and goats when sick

increased respiration and animals are forced to move.heartbeat, prostration

Chenopodium spp. Lambs-quarters Nitrates See nitrate poisoning

Cicuta maculata Spotted water- Cicutoxin Excessive salivation, tremors, Scores of cases of humanhemlock violent convulsions, poisoning from this plant are

abdominal pain recorded in the United States.

Claviceps spp. Tobosagrass Alkaloids Acute - Extreme nervousness, Most cases of Ergot poisoningergot, dallis- muscular trembling, frequent in Texas occur with cattle;grass ergot, urination, ataxia, prostration dallisgrass ergot causes acuteergot of cereal Chronic - Gangrene symptoms.grains

Colubrina texensis Hogplum Hepatic toxin Symptoms similar to Livestock poisoning is rare.lechuguilla poisoning

Conium Poison hemlock, Alkaloids Nervousness, trembling, This plant was used to putmaculatum poison parsley ataxia, dilation of pupils, Socrates to death.

slow heartbeat, coma,congenital crooked calfdisease

Conyza coulteri Coulter conyza Unknown CNS signs, incoordination, Symptoms have not beenblindness, convulsions and proven experimentally.death

Cooperia Giant rain lily Photodynamic See photosensitization Only dead leaf material ispedunculata agents (primary) toxic.

Coydalis a urea Golden Alkaloids Twitching facial muscles, Cattle and horses are not ascorydalis staggering, falling in susceptible as sheep; there is

convulsions, running no evidence of toxicity to goats.motions with feet whenprostrate, diarrhea, bitingnearby objects.

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Scientific Common Basic toxic Typical symptoms Remarksname name principle

Cynodon dactylon Bermuda grass Fungi A variety of symptoms is The plant itself is probablyproduced depending upon not toxic.type of fungus

Datura spp. Jimsonweeds, Alkaloids Thirst, distorted vision, Human poisoning isthornapples uncoordinated movement, relatively common for

high temperature, rapid and children.weak heartbeat, convulsions,death

Delphinium Plains larkspur, Alkaloids Uneasiness, stiff gait, strad- Poisoning is rare in Texas.virescens delphinium dled stance, prostration,

nausea, abdominal pain

Descurainia Tansy mustard Unknown Partial or complete blindness, Generally large amounts arepinnata aimless wandering, pushing required for poisoning to

against solid objects for hours, occur.loss of use of tongue

Drymaria Inkweed, unknown Loss of appetite, diarrhea, Poisoned animals generallypachyphylla thickleaf arched back and “tucked up die before symptoms are

drymary abdomen,” coma noticed.

Eriogonum spp. Buckwheat Photodynamic See photosensitization Most problems are seen inagent (primary) cattle.

Erodium Filaree, heron- Nitrates See nitrate poisoning This plant is considered acicutarium bill, storkbill valuable forage plant.

Erodium texanum Texas filaree

Eupatorium White snake- Tremetol Trembling, depression, weak- Humans can be poisoned byrugosum weed, richweed ness, labored respiration, milk from affected animals.

constipation, blood in feces,odor of acetone in breath

Euphorbia Spotted spurge Photodynamic See photosensitizationmaculata agent (primary)

Euphorbia Snow on the Acrid juice Irritation of mouth and gastro- This plant rarely causesmarginata mountain intestinal tract, diarrhea death; intestinal astringents

should be administered torelieve diarrhea.

Festuca Tall fescue Alkaloids Gangrene which causes loss Poisoning is generally restrictedarundinacea of feet, tip of tail and ears to cattle.

Flourensia cernua Tarbush, Unknown Loss of appetite, abdominal Tarbush is extremely unpalat-blackbrush pain, reluctance to move, able and will not be consumed

occasionally respiratory if alternate forage is available.distress

Gelsemium Yellow jessamine Alkaloids Muscular weakness, stagger- Many children have beensempervirens ing, dilated pupils, convul- poisoned by sucking nectar

sions from the flowers.

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Scientific Common Basic toxic Typical symptoms Remarksname name principle

Gutierrezia Perennial Saponin Listlessness, loss of appetite, Most economic loss is frommicrocephalum broomweed, nasal discharge, fecal mucous, abortion in cattle.

threadleaf bloody urine, vaginalbroomweed, discharge in femalesturpentineweed

Gutierrezia Perennialsarathrae broomweed,

broomsnakeweed,turpentine weed

Helenium Bitter Dugaldin Weakness, staggering gait, Sheep are most often poisonedarnarum sneezeweed diarrhea, vomiting, salivation, in Texas.

bloat, grinding of teeth andretraction of lips, nasaldischarge

Helenium Small head Dugaldin See Helenium amarum Sheep occasionally consumemicrocephalum sneezeweed this very toxic plant in the

rosette stage.

Heliomeris Annual Unknown Not well documented Poisoning has been restrictedlongifolia var. goldeneye to cattle.annua

Hymenoxys Bitterweed Hymenoxon Loss of appetite, cessation Bitterweed slowly increasesodorata of fermentation, abdominal in toxicity with maturity.

pain, bloating, greensalivary discharge

Isocoma wrightii Rayless Tremetol Muscular trembling, standing Poison can be transmitted togoldenrod, in “humped up” position, humans through milk.jimmy weed, stiff gaitalkaliweed

Jatropha Berlandier Purgative oil Vomiting, diarrhea, abdominal This plant is poisonous only tocathartic mettlespurge and phytotoxin pain sheep and goats.

Jatropha dioica Leatherstem Purgative oil Severe gastroenteritis, This plant is poisonous only toand photo toxin vomiting, diarrhea, sheep and goats.

abdominal pain

Kallstroemia spp. Caltrop Unknown Weakness in hind legs and An animal must consumeknuckling of fetlock joint, one-third of its weight inposterior paralysis, caltrop to be poisoned.convulsions

Karwinskia Coyotillo Unknown Seed ingested - Weakness Seeds and leaves producehumboldtiana and incoordination of hind different poisoning syndromes.

legs, exaggerated highstepping, jumping or movingbackwards, prostrationFoliaqe ingested - Loss ofcondition, wasting, nausea,progressive weakness

Kochia scoparia Kochia, Oxalic acid See oxalate poisoning and Poisoning occurs when largesummer and unknown photosensitization (hepatic) quantities are consumed forcyperus 45 days or more.

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Scientific Common Basic toxic Typical symptoms Remarksname name principle

Luntana camara Largeleaf Lantadene A Sluggishness, partial paralysis This plant is an excaped,var. mists lantana and B and bloody diarrhea; also see introduced ornamental plant.

photosensitization (hepatic)

Lathyrus hirsutus Singletary pea Unknown Lameness, incoordination, This is a desirable forage plantrear leg paralysis except in the seed stage; most

lathyrus pusillus Low peavine poisoning occurs with haycontaining maturing plantswith seed pods.

Lobelia Berlandier Alkaloids lncoordination and extreme This plant is limited to deepberlandieri lobelia narcosis South Texas.

Melia azedarach Chinaberry Unknown Stiffness, incoordination, loss Hogs are most frequentlyof appetite, constipation, poisoned.blood stained feces

Melilotus spp. Sweetclover Dicumarol Subcutaneous swelling due to Poisoning is restrictedinternal bleeding, blanching primarily to cattle eatingof visible mucous membranes, moldy hay.weakness

Nerium Oleander Cardiac Abdominal pain, vomiting, This plant is extremely toxic;oleander glycosides diarrhea, trembling, paralysis, even smoke can poison humans.

coma and usually death

Nicotiana Tree tobacco Nicotine and Weak pulse, staring eyes, Cattle and horses are mostglauca alkaloids unsteadiness, stumbling, often poisoned.

trembling, salivation,frequent urination

Nitrate Nitrate Weakness, unsteady gait, Plants containing more thanpoisoning collapse, shallow and rapid 1.0% nitrate are dangerous.

breathing, rapid pulse, coma

Nolina texanna Sacahuista unknown See photosensitization The fruit and flowers contain(hepatic) the toxic agent.

Oxalate Oxalic acid Dullness, colic, depression, Calcium-rich feeds may.poisoning prostration, coma reduce oxalate poisoning.

Oxytropis Lambert loco, Unknown See Astragalus spp. This plant is rare in Texas.lambertii crazyweed,

point loco

Panicum Blue panicum Unknown Labored respiration Blue panicum is a valuableantidotale forage grass; most problems

occur shortly after fertiliza-tion and irrigation.

Panicum Kleingrass Fungus See photosensitization Poisoning generally iscoloratum (hepatic) restricted to sheep and goats.

Peganum African rue Alkaloids Weakness of hind legs and This plant is extremely unpal-harmala knuckling of fetlock joints, stable.

stiffness, trembling, frequenturination, excessivesalivation

14

Scientific Common Basic toxic Typical symptoms Remarksname name principle

Perilla Perilla mint, Ketones Labored respiration This plant is found only infrutescent beefstead East Texas.

plant

Photosensiti- Photodynamic Reddening, swelling of skin Most economic loss is causedzation (primary) agents exposed to sunlight, animal by weight damaged udders and

seeks shade, itching, swelling teats, secondary infection andof coronary band eye damage.

Photosensiti- Green pigments Same as above Same as above, but animalszation (hepatic) and liver damage die more often from liver

damage.

Phyllanthus Abnormal Unknown See photosensitization Poisoning is generallyabnormis leaf flower (hepatic) restricted to cattle.

Phytolacca Pokeweed Alkaloids Abdominal pain, vomiting, Humans use the cooked leafamericana and phytolas- purging, convulsions for greens.

cotoxin

Pinus ponderosa Ponderosa Unknown Abortion This plant is limited to highpine elevations in West Texas.

Portulaca Purslane Oxalic acid See oxalate poisoningoleracea

Prosopis Mesquite unknown Acute - Impaction, colic in Beans must make up most ofglandulosa horses the diet for 60 days to cause

Chronic - Swelling of jaw and poisoning.tongue in cattle

Prunus spp. Wild plum, Hydrocyanic See prussic acid poisoning Bruising, wilting, withering orwildcherry, acid frost damage to leaves increaseschokeberry toxicity.

Prussic acid Hydrocyanic Salivation and labored Sorghum species in Texaspoisoning acid breathing, muscle tremors, most frequently produce

incoordination bloating, prussic acid poisoning.tetanic muscle contractions,convulsions

Psilostrophe Cudweed Unknown lncoordination and stumbling, Sheep can graze these plantsgnaphalioides paperflower sluggishness, loss of for approximately 2 weeks

appetite, coughing causing before poisoning occurs.vomiting of a greenish liquid

Psilostrophe Woolytagetina paperflower

Pteridium Bracken fern Thiaminase Horses - Loss of condition, A large amount of brackenaquilinum var. and unknown incoordination, lethargy, fern is requiredpseudocaudatum standing with legs apart symptoms.

tremors, prostration,convulsions

hemorrhagic syndrome

to produce

Quercus spp. Oaks Tannins Emaciation, edema, consti- Most problems occur in thepation or diarrhea, rough spring when livestock con-haircoat, depression, sume buds, small leaves, stemsdiscomfort and flowers, or in the fall when

15acorns are consumed.

Scientific Common Basic toxic Typical symptoms Remarksname name principle

Ricinus Castorbean Ricin Nausea, violent purging, The lethal dose for humans iscommunis blood in feces, muscular only one or two castorbeans.

tremors, general weakness

Salsola iberica Tumbleweed Nitrates and See nitrate poisoning andoxalic acid oxalate poisoning

Salvia reflexa Lanceleaf Unknown Muscular weakness The toxicity of this plant issafe suspected.

Sartwellia Sartwellia Unknown Gradual weight loss, normal Poisoning is generallyflaveriae appetite, distended restricted to goats.

abdomen

Senecio douglasii Threadleaf Alkaloids Continuous walking, nervous A time lapse of months mayvar. longilobus groundsel disturbances, voiding of occur between consumption

liquid bile-stained feces, may of this plant and the occurrenceSenecio riddellii Ridden attack any moving object of symptoms.

groundsel

Senna Sicklepod senna Unknown Bright, alert downer, weak- Seed pods usually are eatenobtusifolia ness, diarrhea, sometimes after a frost.

dark urineSennaoccidentals Coffee senna

Senna roemeriana Twinleaf unknown Depending on dose, symp- The entire plant is consumedsenna toms maybe same as coffee when in the bloom or early

senna; or may show CNS seed pod stage.signs from liver damage

Sesbania Drummond Unknown Uneasiness, depression, Generally, 1 oz. of seed willdrummondii sesbane, arched back, anorexia, kill sheep and less than 2 oz.

poison bean diarrhea, shallow and rapid will kill large animals.respiration, coma

Sesbania Bagpod sesbane Unknown See Sesbania drummondiivesicaria

Solarium Carolina Solanine Nervous symptoms such as The solanine content of thiscarolinense horsenettle alkaloids trembling, “crazy cow plant was found to increase

syndrome” (fall when excited, ten fold with maturity.can’t get up, roll head or holdit sideways), labored breathingand paralysis or gastrointes-tinal symptoms such as nausea,abdominal pain or diarrhea

Solarium Tread slave, Solanine Hyper-excitement, cows fall Chronic low level consump-dimidiatum western alkaloids when trying to make rapid tion causes “crazy cow

horsenettle movements syndrome;” large amountscause symptoms of otherSolanum spp.

Solarium Silverleaf Solanine See Solanum carolinense Man has also been poisonedelaeagnifolium nightshade alkaloids by silverleaf nightshade.

Solarium rostratum Buffaloburr Solanine See Solarium carolinense In addition to the toxic effectsalkaloids of solanine, the prickles cause

internal irritation whengrazed.

16

Scientific Common Basic toxic Typical symptoms Remarksname name principle

Sophora White loco Alkaloids Not well documented Most losses attributed to thisnuttalliana plant occur in extreme West

Texas.

Sophora Mescalbean, Cytisine, Increased pulse, stiffening Sheep usually recover followingsecundiflora mountain sophonine of hind legs, muscular poisoning; cattle often die.

laurel, frigolito trembling, coma

Sorghum spp. Johnsongrass, Hydrocyanic See prussic acid poisoning; Cattle and horses are mostsorghum, acid horses have rear leg susceptible to poisoning bysorghum alum paralysis, dribbling urine sorghum.

Stillingia Trecul Hydrocyanic See prussic acid poisoning Numerous sheep losses to thistreculiana queensdelight acid plant have occurred in the

Edwards Plateau.

Thamnosma Dutchman’s Psoralens Increased body temperature, Dermal contact transmits thetexana breeches photophobia, edema of photosensitizing effects to

muzzle and vulva humans.

Tribulus Puncturevine, Nitrates and See nitrate poisoning and All growth stages are toxic.terrestris goathead unknown photosensitization (hepatic)

Xanthium spp. Cocklebur Unknown Weakness, depression, Only young plants have beenunsteady gait, nausea, shown to be toxic.vomiting, running motionswith legs when down, markedcurvature of the neck

Zigadenus Nuttall Alkaloid Salivation, nausea, vomiting, All parts of the plant arenuttallii deathcamas depression, weakness, low poisonous, even when dry.

temperature, weak andirregular pulse, irregularbreathing, coma

17

Educational programs of the Texas Agricultural Extension Service are open to all people without regard to race, color, sex, disability, religion, age ornational origin.

Issued in furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of Congress of May 8, 1914, as amended, and June30, 1914, in cooperation with the United States Department of Agriculture. Zerle L. Carpenter, Director, Texas Agricultural Extension Service, TheTexas A&M University System.5M--8-94, Reprint RS 3-3