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COLLECTION: GOAT HANDBOOK
ORIGIN: United States
DATE INCLUDED: June 1992
Extension Goat Handbook
This material was contributed from
collections at the National Agricultural Library.
However, users should direct all inquires about the
contents to authors or originating agencies.
DOCN 000000025
NO C-4
POISONOUS PLANTS
D. L. Ace L. J. Hutchinson; Pennsylvania State U.,
University Park
G. F. W. Haenlein; U. of Delaware, Newark
Nutrition
1 Factors contributing to plant poisoning are starvation,
accidental eating and browsing habits of animals.
Starvation is the most common reason. Most woodland
or swampy-ground pastures contain many species of
poisonous plants. These are usually eaten only when
animals have nothing else to eat.
2 Certain plants are accidentally
eaten by animals as they graze. A notable example
of this is water hemlock. This plant emerges in wet
areas which are the first to become green in early
spring. Animals eager to eat the fresh young grass
may accidentally bite off the crown of this plant
with fatal results. Another type of accidental poisoning
occurs when large amounts of cockle are present in
wheat which is fed as grain.
3 Some animals on good feed in a
dry lot or excellent pasture become bored with the
same regular diet. They may eat unpalatable weeds
or ornamental plants growing along fences. Goats and
cattle like to vary the best kind of diet with a little
''browse''. Many ornamental or wild shrubs may be
consumed, not because they are palatable but because
the animal craves variation in its diet.
4 The severity of poisoning is related
to the quantity of material eaten, the specie of animal
eating the plant, portion of the plant and condition
of the plant eaten, level of ground moisture, general
health of the animal prior to ingesting the substance
and the age and size of the animal. Therefore some
livestock can eat some of the bad plants and under
several of the mentioned conditions, fail to show
symptoms of injury or poisoning. At other times death
may occur.
5 Scores of plants contain material
toxic to animals if eaten in sufficient quantity.
Some of the plants are well known, some quite rare,
some are useful, others are valued ornamentals. They
may be grouped by the type of poison contained, the
effect of their toxins or the part of the plant containing
the poison. Some plants may contain several poisonous
principals.
6 Cyanogenetic Plants These contain
under certain conditions, prussic acid (hydrocyanic
acid), a deadly poison which interfers with the oxygen-carrying
ability of the blood. Death in these cases is usually
rapid and with little outward symptoms. Members of
the prunus family of plants, especially wild cherries,
are dangerous. Peaches, plums and other stone fruits
belong to this group of plants. Wilting of the green
leaves caused by frost, storm damage, or by cutting,
changes a glucoside found in the leaves to hydrocyanic
acid (HCN) and sugar. The sweet, wilted leaves are
thus more attractive to animals than normal foliage.
HCN content varies widely; but under some conditions
a few handfuls of leaves may be enough to kill a horse
or cow. This type of poisoning should be suspected
when sudden death of animals follows windstorms or
early sharp frosts. These leaves apparently lose their
poison after they have become dry; the limp, green
or partially yellowed leaves are the most dangerous.
Sudan grass and sorghums are also cyanogenetic plants.
These plants are usually deadly when damaged or frozen.
Aftermath sprouts following an early frost are particularly
dangerous. Very little sudan grass poisoning occurs
from animals trampling down plants and later eating
them although this is often listed as dangerous. In
dry weather, sudan grass is often pastured to the
ground without ill effects. After sudan grass has
been repeatedly frozen and the plants are completely
dead, it is safe but not very valuable for pasture.
7 Once frozen, sorghum, sorghum sudan
hybrids, or their aftermath should never be pastured.
As long as the plants show any green color they may
be very poisonous. Both frosted sorghum and sudan
grass can be best and most safely utilized by ensiling
them for at least two weeks before feeding. Normal
ensilage fermentation safely eliminates the poisonous
principle.
8 Common milkweed, a perennial that
grows three or four feet high, has a heavy stem and
leaves and is frequently found in pastures. The milky
white sap is sticky and has a bitter taste but livestock
eat the topmost, tender leaves if good forage isn't
abundant. Remove plants by spading, pulling, cutting
or plowing extensive areas and planting to cultivated
crops for a year or two.
9 Horse nettle is a perennial plant,
two-feet-high, with spiny stems and leaves, and smooth,
orange-yellow berries. Fruits are more toxic than
the foliage. It's a common plant in grasslands and
fields and is a member of the nightshade family.
10 Black nightshade is an annual
plant, two-feet high, with many branches. Leaves are
variably smooth or hairy. The stems angled in cross-section
and sometimes spiny. Clusters of white flowers, one-fourth
inch across, bloom in midsummer and are followed by
small, black fruits. Both the foliage and green berries
are toxic. The ripe berries are not poisonous. Black
nightshade is widely distributed.
11 Mountain laurel is an evergreen
shrub of the Appalachian Mountain region. Plants grow
five-feet tall and have glossy green leaves. Flowers
appear in clusters at the ends of branches. Livestock
eat the leaves in early spring when little other foliage
is available. Weakness, nausea, salivation and vomitting
are symptoms of poisoning. The preventative is to
keep livestock out of areas where mountain laurel
is abundant.
12 Plants Containing Deadly Alkaloids
Fortunately these plants are unpalatable for most
wild and domestic animals. Water hemlock and poison
hemlock are deadly. Poisoning rarely occurs except
in early spring when young plants are accidentally
eaten, but the roots, stems, leaves and flowers are
always poisonous. Look for and learn to identify these
plants in the summer when they are large and showy.
The hemlocks are members of the carrot family and
have showy, white, umbrella-like flower heads. Poison
hemlock needs dry land to grow and is often found
in gardens as an ornamental plant. Flowers are often
incorporated into large mixed flower sprays in rural
churches and at social events.
13 Water hemlock - a perennial frequently
found in wet, fertile soil - is a five-foot-tall plant
with thick rootstocks, doubly compound leaves (fernlike)
and small white flowers in umbrella-like clusters.
14 The roots are the most poisonous
parts of the plants. Cut the thick rootstocks lengthwise
and you'll find air cavities separated by plate-like
partitions of solid tissue. Drops of yellowish, aromatic,
resin-like exudate containing the poisonous alkaloid
appear at the cuts. Leaves and seeds contain little
of the toxic substance and eaten in small quantities,
either green or in hay, do little harm.
15 Water hemlock starts growth in
early spring. Its green foliage may show up before
most other plants leaf out. Livestock tug at the tender
leaves and pull roots from the soil which are still
soft from late winter rains. The combinations of foliage
and roots in considerable quantity can be fatal.
16 As a preventative, pull water
hemlock plants from the soil during the summer when
they can readily be found and destroy them. Plants
usually are not numerous in an area.
17 Poison hemlock is a hollow-stemmed
biennial, four-feet high, with double compound leaves
resembling parsley and a large, white taproot like
parsnip. Flowers are showy, umbrella-like clusters
and appear in late summer. The poison is a volatile
alkaloid, coniine, found in the foliage all season
and in the seeds in late summer. Most livestock poisoning
comes in the spring from eating fresh foliage.
18 Mayapple, bloodroot, pokeweed,
nightshade and hellebore are other alkaloidal plants.
They are rarely eaten except when animals are starving
for better feed. Deaths from alkaloidal plants usually
result from severe digestive disturbances, pain and
nervous symptoms. Animals usually die in convulsions.
19 Plants That Are Photodynamic This
means photo-sensitive animals get a reaction. Conditions
necessary for a reaction to occur are: 1) the animals
must have white areas of skin (unpigmented); 2) the
animals must eat a sufficient quantity of the plants;
and 3) the animals must be exposed to bright sun.
In typical cases, an animal suddenly becomes sore
on the white areas of their bodies. Whole areas of
white skin may raise up and slough off. White goats
may become severely affected and die from this condition.
20 Some common plants which cause
photosensitization are rape, alsike clover, buckwheat,
lantana, St. John's wort, and ornamental hypericums.
Both St. John's wort and ornamental hypericums have
showy, golden-yellow flowers. They are not readily
eaten by animals. White goats frequently become badly
''sunburned'' when they are on rape pasture in bright,
sunny weather with little or no shade. Alsike clover
or other legumes may produce these symptoms in dairy
goats under the above conditions.
21 Plants That Produce Mechanical
Injury A number of plants may have a spiny covering,
long beards, fine hairs and when eaten may cause mechanical
injuries or form hair balls in the stomach and intestines.
Sand bur, downy brome grass, squirrel-tail grass,
poverty grass, mesquite, cocklebur and clover are
some of the offending plants.
22 Some Other Poisonous Plants Comparatively
few plants containing poisons grow in areas usually
used as pastures.
23 Bracken fern is very common in
wooded areas and unimproved pastures. Most animals
will not eat bracken fern if there is adequate pasture
or other feed. In ruminants, such as goats, bracken
fern must be consumed over a period of several weeks
before toxicity signs develop. Affected animals are
listless, show weight loss and may exhibit small hemorrhages
on the mucous membranes. They may die from internal
hemorrhages.
24 Buttercups contain an acrid, volatile
alkaloid-amenenol, strong enough to blister the skin
and cause inflammation of the intestinal tract. Cattle
and goats poisoned by buttercups produce bitter milk
and a reddish color. The toxic material volatilizes
and is lost when buttercups are dried as in hay.
25 A heavy growth of buttercup is
an indication of low soil fertility. Have the soil
analyzed and apply ground lime and fertilizers as
their need is shown. The increased grass growth soon
crowds out buttercups.
26 Poison ivy is widespread over
most of the United States. It's a shrub or vine with
woody stems that climb by attaching aerial rootlets
to fences, walls, trees, etc. Leaves have three leaflets,
glossy green and smooth at the edges. Inflammation
of the skin from contact with the plants is an affliction
of goat-keepers more frequently than of goats. The
infection can become serious and may need medical
attention. Kill poison ivy with a herbicide.
27 Several ornamental plants that
are green outdoors or indoors are highly toxic. Goats
should not be fed clippings from ornamental plants.
Common poisonous ornamentals are yew, delphinium,
oleander, larkspur and lily-of-the-valley. Goats should
not be allowed access to these plants.
28 NOTE: USDA and the State Department
of Agriculture in each state can offer help in providing
reference material on poisonous plants.
29 A Listing of Some Plants Known
to Cause Problems When Eaten by Livestock (Source:
Stock Poisoning Plants of North Carolina, Bulletin
No. 144, by James Hardin; Plants Poisonous to Livestock
in the Western States, USDA Information Bulletin No.
415; Poisonous Plants of Pennsylvania, Bulletin No.
531, PA Department of Agriculture)
30 Cyanogenetic Plants (Glucosides
- Glycosides) Arrow grass Black Locust Blue Cohosh
Broomcarn Buckeye (Horse chestnut) Cherry Choke Cherry
Corn Cockle Dogbane Elderberry Hemp Horse Nettle Indian
Hemp Ivy Johnson grass Kafir Laurel Leucothoe Lily
of the Valley Maleberry Marijuana Milkweeds Milo Nightshade
Oleander Rhododendron Sevenbark Silver Sneezewood
Sorghum Stagger brush Sudan grass Velvet grass White
snakeroot Wild Black Cherry Wild Hydrangea
31 Alkaloid Containing Plants Aconite
Allspice Black Snake Root Bloodroot Blue Cohosh Boxwood
Celandine Common Poppy Crotalaria Crow Poison Death
Camas Dicentra False Hellebore False Jessamine Fume
wort Hellebore Hemp Horse Nettle Indian Hemp Indian
poke Jimson weed Larkspur Lobelia Lupines Marijuana
Monkshood Moonseed Night shade Pink Death Camas Poison
Darnel Poison Hemlock Poison rye grass Rattleweed
Rock Poppy Spider Lily Spotted cowbane Spotted Water
Hemlock Stagger grass Staggerweed Sweet Shrub Thorn
Apple Varebells Wild Parsnip Wolfs-bane Yellow Jessamine
32 Volatile or Essential Oils as
Poisonous Principle Baneberry Buttercups Crowfoot
Ground Ivy Lobelia Snakeberry Spurge White Cohish
33 Saponin Containing Plants Bagpod
Coffee weed Purple sesban Rattlebox Soapwort
34 Photosensitizing Plants Buckwheat
Goat weed Klamath weed Lantana Rape St. John's Wort
35 Plants That Cause Mechanical Injury
Clover Cocklebur Downy Brome grass Sand Bur Squirrel
tail grass
36 Tannin (Tannic Acid) as Poisonous
Principle Oaks
37 Poisonous Principle Not Exactly
Known Inkberry Poke weed
38 Resins as Poisonous Principle
Discarded Christmas trees Ponderosa Pine needles
POISONOUS PLANTS
COLLECTION;GOAT HANDBOOK
ORIGIN;United States
DATE_INCLUDED;June 1992
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