This presentation is from the 5th and final webinar in the 2015 webinar series, Pasture Management for Small Ruminant Producers.

1. 2015 WINTER WEBINAR SERIES
PASTURE MANAGEMENT FOR SMALL
RUMINANT PRODUCERS
V. PASTURE HEALTH
SUSAN SCHOENIAN & JEFF SEMLER - UNIVERSITY OF MARYLAND EXTENSION
SMALL RUMINANT PROGRAM

2. HEALTH PROBLEMS OF GRAZING ANIMALS
• Bloat (rumen tympany)
• Ergot alkaloids (fescue toxicosis)
• Gastro-intestinal parasites
• Grass tetany
• Nitrate and prussic acid poisoning
• Poisonous plants
• Phytoestrogens
• Predation

3. BLOAT (RUMEN TYMPANY)
• Overextension of the rumen and reticulum,
gas is trapped; animal is unable to belch
(eructate).
• More common in cattle, but is not uncommon
in goats and especially sheep.
• Can be a life-threatening condition.
• Clinical signs: distended abdomen
(left side), unusual postures, lateral
recumbency, pain, restlessness, frequent
urination/defecation, discomfort – and
sudden death.
• Can also be a normal post-mortem change.

4. BLOAT (RUMEN TYMPANY)
PRIMARY, NUTRITIONAL, OR FROTHY BLOAT
• Entrapment of the normal gases of fermentation in a stable
foam.
1. Pasture bloat
• Most common in animals grazing legume or legume-
dominated pastures, particularly alfalfa, ladino, and red and
white clovers.
• Also seen in animals grazing young green cereal crops, rape,
kale, turnips, and vegetable crops.
• Can also occur when animals are grazing wet grass pastures.
2. Feedlot bloat
• Occurs in feedlot due to high carbohydrate grain diet or
feeding of finely-ground grains.
SECONDARY OR FREE GAS BLOAT
• Gas cannot be expelled
because of extraruminal
obstructions to outflow.
• Secondary tympany can
occur with unusual
postures, e.g. lateral
recumbency, “cast”
• May also develop with
hypocalcemia.

5. BLOAT (RUMEN TYMPANY)
TREATMENT
• Remove blockage
• Make animal belch
• Pass tube into stomach
(free gas bloat only)
• Drench with anti-foaming agent:
vegetable oils, mineral oil,
poloxalene (e.g. Therabloat®),
simethicone preparations (e.g.
Mylanta®).
• Puncture the rumen to relieve gas
(last resort, Vx).
PREVENTION
• Reduce amount of legume in pasture.
• Incorporate non-bloat-forming legume: birdsfoot
trefoil, crown vetch, and sericea lespedeza.
• Gradual access to at-risk pastures.
• Delay grazing until after dew has lifted.
• Feed dry hay before letting animals out to large
amounts of succulent feed.
• Feed antifoaming agent (e.g. poloxalene) or
ionophore (e.g. Bovatec®, Rumensin®).
• Monitor animals for signs of bloat.
Morelife-threatening

6. ERGOT ALKALOIDS - FESCUE TOXICOSIS
• Tall fescue is the primary cool season grass in the
Eastern US.
• Kentucky 31 tall fescue contains an endophyte (fungus)
that produces ergot alkaloids (toxin).
• Ergot alkaloids alter systems of the body that are
controlled by neurotransmitters (brain chemicals):
heart, blood, appetite, hormonal, gut motility, muscle
contractions, and body temperature.
• Signs of fescue toxicosis vary by livestock species.
• Sheep seem to be less affected than cattle.
• Limited information is available on goats.
• Cost to small ruminant industry is unknown
• $500-$1 billion cost to beef industry.

7. SOME POTENTIAL EFFECTS OF FESCUE TOXICOSIS SYNDROME
(some scientifically-proven*, some antidotal) -- mostly sub-clinical
HEALTH/WELFARE
• Fescue foot
• Fat necrosis*
• Rough hair coats
• Heat stress*
GROWTH
• Suppressed appetite*
• Lower intake*
• Reduced weight gain*
REPRODUCTION
• Prolonged gestation
• Thickened placentas
• Reduced fetal growth*
• Weak offspring
• Poor mothering
• Reduced milk*
production
• Agalactia*

8. MINIMIZING THE EFFECTS OF FESCUE TOXICOSIS
• Dilute endophyte-infected tall fescue with other grasses or
legumes.
• Replace endophyte-infected tall fescue with another forage,
e.g. endophyte-free or novel tall fescue varieties (e.g. MaxQ™
tall fescue).
• Increase stocking rates to prevent plant maturation and seed
head formation (fungus concentrates near seed head).
• Avoid summer grazing and N fertilization.
• Stockpile for fall and winter grazing, when effects of endophyte
are less.
• Alter nutritional management by providing supplemental feed
to dilute endophyte.
• Don’t breed on endophyte-infected pastures.
• Feed mineral mixes specifically formulated for sheep or goats.

9. GASTRO-INTESTINAL PARASITES
• Number one problem affecting small ruminants
that graze.
• Many types of internal parasites can infect small
ruminants, but the barber pole worm
(Haemonchus contortus) and coccidia (Eimeria
spp.) are usually the most important.
• Sheep and goats share same parasites; only
coccidia is species-specific.
• Risk of clinical parasitism (i.e. treatment
required) varies by species, genetics, production
system, and climate.
• Parasite resistance varies by species, breed, age,
and genetics.

10. INTEGRATED PARASITE MANAGEMENT (IPM)
1) MANAGEMENT
• Pasture rest and rotation
• Clean pastures
• Mowing and haying
• Multi-species grazing
• Alternative forages
• Minimum grazing height
• Zero grazing
• Nutritional supplementation
• “Natural” products
• Genetic selection
2) PHARMACEUTICAL (DEWORMERS)
• Targeted selective treatment (TST)
Requires regular monitoring of livestock
1. FAMACHA© scoring
2. Five Point Check©:  eye,  back, rear,
 jaw, and  nose (or coat).
• Periparturient treatment/management
• Proper use of anthelmintics.
• Periodic testing for anthelmintic resistance.

11. GRASS TETANY (STAGGERS) – HYPOMAGNESEMIA
• Low blood Magnesium (Mg).
• Caused by low level of magnesium in growing forages
and an interference of with the absorption of Mg due
to various factors.
• Most common in nursing females during early
lactation, specially during late winter, early spring.
• More common in cows than ewes and does.
• Causes hyperexcitability, muscular spasms,
convulsions, respiratory distress, collapse, and death.
• Diagnosis is usually confirmed by response to
treatment.

12. GRASS TETANY
TREATMENT
• Combined solutions of calcium and
magnesium via IV
PREVENTION
• Magnesium supplementation
• Supplemental feeding of hay and/or
grain.

13. NITRATE AND PRUSSIC ACID POISONING
NITRATE/NITRITE
• Under normal circumstances, nitrate is converted to ammonia,
then bacterial protein. There is little build-up in the plant.
• When higher amounts of nitrate are consumed, an accumulation
of nitrite may accumulate in the rumen.
Nitrates (NO3)  Nitrites (NO2)
• Nitrite is absorbed into bloodstream and will convert hemoglobin
to methemoglobin, which is unable to transport oxygen.
• Animals dies from nitrate poisoning, due to lack of oxygen
• Sheep have the highest tolerance to nitrates because they have the
greatest ability to convert methemoglobin back to hemoglobin.
• Water can also be high in nitrates.
PRUSSIC ACID (CYANIDE)
• Sorghum family plants contain a
secondary compound called dhurrin,
which is enzymatically converted to
toxic prussic acid in wilting forages.
• Dangerous wilting can be caused by
drought, frost, cutting, trampling or just
chewing.
• Leaves contain more toxin than stems.
• Prussic acid interferes with ability of
blood to carry oxygen, causing animals
to die from suffocation.

14. HISTORICAL PERSPECTIVE ON NITRATE POISONING
• First reported over 100 years ago in
connection with deliberate attempts to
poison sheep on disputed ranges.
• “Salting the range” to get rid of “range
maggots” (sheep).
Ranchers spread KNO3 on range to
poison sheep on “cattle” ranges.

15. NITRATES AND PRUSSIC ACID POISONING
NITRATES
• Some plants are more likely to
accumulate nitrates than others.
• Annual forage crops: corn, small
grains, sudangrass, and sorghum
• Weeds: pigweed, lambsquarter,
sunflower, bindweed, and others.
• Vegetables: sugar beets, lettuce,
cabbage, potatoes, and carrots.
PRUSSIC ACID (CYANIDE)
• Prussic acid can form in young
sorghum-type plants or in the leaves of
stressed sorghum-type plants: forage
sorghum, sorghum x sudangrass,
sudangrass, and johnson grass
• Prussic acid can also form in other
plants: common milkweed,
Horsenettle, Black nightshade,
Mountain Laurels, rhododendrons, and
evergreen shrubs

16. REDUCE RISK OF NITRATE POISONING
NITRATES
• Delay harvest or grazing after a drought ending rain
• Split nitrogen applications
• Raise cutting or grazing height
• Test all suspect forages
• Harvest forage as silage
(nitrates are stable in hay)
• Avoid feeding high nitrate forage to susceptible animals
• Limit intake of high nitrate forages
• Conditioning
• Healthy animals
• Adequate carbohydrate consumption

17. REDUCE RISK OF PRUSSIC ACID POISONING
PRUSSIC ACID
• Avoid grazing young plants and new
growth.
• Avoid grazing drought-stressed plants.
• Avoid grazing frosted plants.
• Make sure hay is properly cured before
baling.
• Feed green chop in timely manner.
• Feed good quality hay or silage before
grazing questionable forages.
• Use tester animals to evaluate
questionable forages.

18. PHYTOESTROGENS
• Some pasture legumes contain chemicals called
phytoestrogens, which can affect the reproductive system.
• Phytoestrogens have a similar chemical structure to
mammalian estrogen.
• Content is high in legumes, including alfalfa, soybeans,
and clovers, red, white and especially subterranean.
• Can cause fertility problems in female ruminants,
especially sheep: infertility, low lambing rates, uterine
prolapse, and dystocia (documented mostly in Australia
with Subterranean clover).
• The advantages of red clover in sheep (and goat) pastures
probably outweighs the risk of their phytoestrogenic
content.
• To err on the side of caution, don’t breed on pastures that
contain too much red or subterranean clover.

19. POISONOUS PLANTS
• Many plants can be poisonous to sheep, goats,
and other livestock.
• Toxicity depends upon many different factors:
plant, plant part, stage of growth, environmental
conditions, time of year, amount consumed, and
type of livestock (species, age, sex, condition)
• Poisonous/toxic plants can cause sudden death,
photosensitization, and neural symptoms.
• May be cause of unexplained death(s), as most
deaths go undiagnosed.

20. POISONOUS PLANTS: PREVENTION AND CONTROL
• Learn to identify poisonous plants in your area.
• Inspect for poisonous plants prior to grazing.
• Do not allow hungry or thirsty animals to graze
areas where poisonous plants are known to exist.
• Provide water daily.
• Provide mineral/salt supplementation year-round.
• Eliminate (control) poisonous plants with
herbicides and/or plowing, digging, and mowing
prior to seed maturation.
• If there is enough to eat, livestock will not usually
eat toxic plants.

21. PREDATION
• Predation accounts for significant losses in the US small
ruminant industry: ~37 percent of total sheep and lamb
losses (APHIS 2004).
• Sheep and goats have many potential predators, including
coyotes, dogs, foxes, wolves, mountain lions, bobcats (lynx),
bears, and various birds of prey (eagles, vultures, owls, and
ravens).
• According to USDA APHIS, coyotes and dogs account for the
largest percentage of losses.
• Predator risk varies by farm/ranch and geographic area.
All small ruminant farms should have a predator
management plan (before any losses occur).

22. METHODS OF PREDATOR MANAGEMENT
NON-LETHAL
• Fencing
• Livestock guardians
• Shed lambing
• Night penning
• Fright tactics
• Herding
• Removing carrion
• Culling old, sick, injured animals.
• Having a good relationship with neighbors,
animal control, DNR, and Wildlife Services.
LETHAL
• Hunting / shooting
• Trapping
• Denning
• Poisoning
 You must follow the laws when using any
lethal method of control. Laws vary by state.
Many predators are protected species.

23. FENCING
1. Multi-strand, high-tensile electric
2. Woven wire with electric offset or
trip wires.
3. Electric netting
4. Barbed wire
LIVESTOCK GUARDIANS
1. Livestock protection dogs:
Akbash
Anatolian Shepherd
Cão de Gado Transmontano
Great Pyrenees
Kangal
Karakachan
Komondor
Maremma
Polish Tatra
Tibetan Mastiff
2. Llamas
(intact male)
alpacas(?)
3. Donkeys
(intact male)
miniature (?)

24. FOR LINKS TO RECORDINGS,
POWERPOINT PRESENTATIONS,
AND YOUTUBE VIDEOS, GO TO
HTTP://WWW.SHEEPANDGOAT.COM
/RECORDINGS.HTML
SUSAN SCHOENIAN
Sheep & Goat Specialist
University of Maryland Extension
sschoen@umd.edu
SMALL RUMINANT PROGRAM