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Grazing Factsheets
Animal Heath
Control
of Parasites in
Grazing Beef Cattle
Control
of Internal
Parasites in Sheep
Control
of Parasites
in Dairy Cattle
Control
of Parasites in Equine
Bloat and Pasture
Ergot and Cattle Health
Pink Eye in Cattle
Anti-Quality Factors in Rangeland and Pastureland Forages
Neosporosis-Abortion in Cattle
Diseases (Being Developed)
Toxicities/Poisoning (Being Developed)
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Animal
Health
Control
of Parasites in
Grazing Beef Cattle
Illinois
|
|
Unless in total confinement,
cattle will be exposed to parasites that result in production
loss and, perhaps, health problems. Control of internal parasites
can be accomplished by administration of any of several oral, injectable or pour-on products available on the market. Too often
the decision to deworm cattle is based on their appearance. By
the time the effects of parasitism are visible, major economic
loss and health compromises have occurred. The issue is when
and how often to deworm cattle relative to the herd exposure
and re-infection. Optimum parasite control for grazing cattle
relies on strategic deworming in order to decrease re-infection.
We must treat the pasture as well as the animal.
- Worm larvae survive winter and
are infectious until late spring
- Warm, wet weather increases
worm larvae viability
- Worm larvae populations from
pastures in spring can be excessive and cause disease in cattle
- Ingested larvae mature to adult
worms, produce eggs which pass out with the feces and further
contaminate the pasture
- Ostertagia sp., specifically, has the ability to
encyst in the wall of the abomasum to later flood the intestinal
tract with a high larvae population
- Pasture reinfection from infected
cows readily provides larvae for calves (which are less resistant
to worm deleterious effects) as well as cows
Figure 1. Over-wintered parasitic larvae provide
re-infection for cows put on spring pastures who perpetuate the
pasture parasite contamination and provide exposure to new calves.**

Goal is to maintain parasite
safe pastures
- Kill adult worms before grazing
- Kill immature worms before egg shedding
- Time treatments to seasonal grazing pattern
Deworm cattle at the end of the grazing season to prevent carry-over
of worms (worming after the first frost with some products will
also kill external parasites)
Deworm cattle a few weeks after
putting on pasture to kill newly acquired worms before they mature
and begin laying eggs to reduce pasture recontamination
- A dewormer which can kill immature worms will be necessary
to use at this time (one that kills only adults will not be effective)
Young animals are more susceptible
to worm infections and should be treated three to four weeks
after turnout followed by several repeat treatments three to
four weeks apart
- (longer than four weeks can allow for sufficient maturation
of the parasite to allow shedding of eggs)
Pasture contamination is related
to grazing pressure
- Dragging pastures to break up and dry fecal pats reduces
larvae numbers
- Intensive grazing practices intensifies the need for parasite
control strategy
Contact your veterinarian
- Optimum product type for specific control period
- Strategies for dewormer administrations to coincide with
other cattle handling requirements
(e.g., vaccination, pregnancy examination, etc.)

Figure 2. Deworm cattle before turning out to pasture
and following treatments to avoid recontamination of pasture**
**Bliss DH: The Cattle Producers
handbook for Strategic Parasite Control. Hoechst Roussel Vet,
1997
Additional Fact Sheets:
-Control of Equine Parasites -R.D. Scoggins, DVM, University
of Illinois
-Control of Internal Parasites in Sheep R.D. Scoggins,
DVM, University of Illinois
-Control of Parasites in Dairy Cattle Dick Wallace, DVM,
MS, University of Illinois
Project funding provided by:
North Central Region Sustainable Agriculture Research and Education
Program
Project coordinated by: Dean
Oswald, Animal Systems Educator, Macomb Extension Center, 480
Deer Road, Macomb, IL, 61455.
The U.S. Department of Agriculture (USDA) prohibits discrimination in
all its programs and activities on the basis of race, color, national
origin, age, disability, and where applicable, sex, marital status,
familial status, parental status, religion, sexual orientation, genetic
information, political beliefs, reprisal, or because all or a part of an
individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities
who require alternative means for communication of program information
(Braille, large print, audiotape, etc.) should contact USDA's TARGET
Center at (202) 720-2600 (voice and TDD). To file a complaint of
discrimination write to USDA, Director, Office of Civil Rights, 1400
Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800)
795-3272 (voice) or (202) 720-6382 (TDD). |
|
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This Factsheet
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Animal
Health
Control
of Internal
Parasites in Sheep
Illinois
|
By: R. D. Scoggins, D.V.M., Extension
Veterinarian,
University of Illinois College of Veterinary Medicine
Internal parasites of sheep
are one of the most costly diseases that sheep producers have
to contend with. Parasite damage may range from reduced productivity
to death losses. Most internal parasites either suck blood or
destroy tissue. The resultant damage may cause the animal to
remain unthrifty for life.
Most midwestern universities
involved with sheep have done extensive research in internal
sheep parasites and their control.
Control is based on a combination
of drug treatment and management to reduce reinfestation. Preventing
animals from being reinfested can eliminate parasites over a
period of time. This is not feasible under most production conditions
except by using expanded metal flooring. Work at Dixon Springs
Agricultural Research Center several years ago showed the value
of expanded metal floors for controlling parasites and foot rot.
Sheep have a number of characteristics
that make them more susceptible to parasites than other livestock.
1. Sheep parasites are mostly blood-suckers.
2. Sheep tend to be very close grazers therefore contacting large
numbers of larvae.
3. Unlike other animals, sheep have little aversion to grazing
amidst heavy fecal contamination.
4. Their strong flocking instinct encourages them to graze close
together.
5. Sheep parasites are prolific egg producers.
6. Sheep develop very little immunity to protect them against
parasites.
Parasites may produce obvious
symptoms to almost no symptoms, depending on
the severity or parasite load. Poor doing animals
may exhibit diarrhea, weight loss, sudden paleness of mucous
membranes, weakness and even death. Severe damage has usually
occurred by the time symptoms appear.
A veterinarian should conduct
a physical exam. A fecal egg count and even an autopsy may be
needed to evaluate the problem. It is important to determine
which parasites are present and at what level of infestation.
Pasture is the most risky management
method for spreading parasites. Infective larvae develop on the
grass stems protected by shade and moisture. Every mouthful of
grass carries infective larvae into the sheep.
Heat and dryness are most effective
in controlling parasite larvae. Midwest winters have relatively
little effect against infective larvae.
Control programs using dewormers
vary in how they are used. Some elect to deworm on a regular
schedule, every 6-8 weeks. Others deworm strategically at specific
times in the production cycle while others deworm based on increasing
fecal egg counts. The most effective ones have a veterinarian
involved who monitors the program and checks the results of treatment.
Fecal egg counts before treatment
identify the kinds of parasites and the level of infection. Samples
checked following treatment should be 7-10 days after treatment.
Samples should be fresh and represent at least 20% of each group
of sheep.
Following treatment, sheep should
be moved to clean pasture or a clean environment to reduce reinfestation.
Treatment is only one aspect of parasite control.
For treatment to be effective, the following considerations are
important:
1. Use the correct medication.
2. Must be used at the correct dosage.
3. Appropriate timing/interval.
4. Fecal examination 7-10 days following treatment.
A number of medications are available
for treating parasitized sheep. There are basically four families
of dewormers.
1. Ivermectin
2. Pyrantel
3. Benzimidazoles
4. Levamisole
This does not include inophores
or other medications for the treatment of coccidiosis.
Use of medication depends on:
1. Type of parasite being treated, i.e., ivermectin does not
kill tapeworms or flukes.
2. Correct route of administration: all have an oral drench formulation
that is effective.
3. Proper dosage based on weight so determine correct weight.
4. Be sure dose is swallowed. Many small producers use horse
paste wormers that sheep frequently spit out.
It is important to work with
a veterinarian to monitor the program to be sure it is effective.
Unnecessary treatments, use of
an inappropriate drug or using the wrong dosage are all expensive
and inappropriate.
Each program should be designed
for the individual circumstances. Two neighbors may need to have
quite different programs depending on their individual circumstances.
One possible scenario based on
management would be:
1. Deworm ewes - 2 weeks before breeding as part of the flushing
process.
2. Deworm ewes - 30 days prior to lambing.
3. Deworm ewes - at lambing time.
4. Deworm ewes - at weaning.
If fecal egg counts warrant,
deworm or check whenever animals appear not to be doing well.
This program would be for ewes lambing in confinement and lambs
weaned before going to pasture.
Other management systems would require different parasite control
strategies.
Additional Fact Sheets:
-Control of Equine Parasites R.D. Scoggins, DVM, University
of Illinois
-Control of Parasites in Dairy Cattle Dick Wallace, DVM,
MS, University of Illinois
-Control of Parasites in Grazing Beef Cattle - G. L. Meerdink,
DVM, University of Illinois
Project funding provided by:
North Central Region Sustainable Agriculture Research and Education
Program
Project coordinated by: Dean
Oswald, Animal Systems Educator, Macomb Extension Center, 480
Deer Road, Macomb, IL, 61455. |
The U.S. Department of Agriculture (USDA) prohibits discrimination in
all its programs and activities on the basis of race, color, national
origin, age, disability, and where applicable, sex, marital status,
familial status, parental status, religion, sexual orientation, genetic
information, political beliefs, reprisal, or because all or a part of an
individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities
who require alternative means for communication of program information
(Braille, large print, audiotape, etc.) should contact USDA's TARGET
Center at (202) 720-2600 (voice and TDD). To file a complaint of
discrimination write to USDA, Director, Office of Civil Rights, 1400
Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800)
795-3272 (voice) or (202) 720-6382 (TDD).
|
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This Factsheet
PDF |
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Animal
Health
Control
of Parasites in
Grazing Dairy Cattle
Illinois
|
By: Dick Wallace, DVM, MS Dairy Extension Veterinarian, University of
Illinois Extension
• Consider the parasite life cycle(s) when designing a parasite control
program.
• Evaluate the relative risk factors for the class(es) of animal(s) to be
treated.
• Consider meat and milk withholding times before administration of the
drug(s).
Birth – Weaning (2 months):
Housing types:
Hutches, individual pens
Group pens
Pasture - rarely
Parasites to control: Coccidiosis, Fleas
Control measures:
1) Sanitary surroundings and good hygiene, control barn cats
2) Medicated milk replacers
|
Trade name |
Generic name |
Label use |
Dosage |
Precautions |
|
Corid |
Amprolium |
Treatment |
10 mg/kg, feed or water, 5 days |
Meat withdrawal
24 hours |
|
Sulfas (various manufacturers) |
Sulfaquinoxaline |
Treatment |
8-70 mg/kg, water, 7 days |
Meat withdrawal
5 days |
|
Bovatec |
Lasalocid (Ionophore) |
Preventative |
100-360 mg/ head/day |
No meat
withdrawal |
|
Corid |
Amprolium |
Preventative |
5 mg/kg, feed or water, 21 days |
Meat withdrawal
24 hours |
|
Deccox |
Dequinate |
Preventative |
0.5 mg/kg, feed, at least 28 days |
No meat withdrawal |
|
Rumensin |
Monensin (Ionophore) |
Preventative
(>400 lbs) |
100-360 mg/head/day |
No meat withdrawal |
Control Program:
- Maintain sanitary environment, reduce exposure to manure from other
cows and calves.
- Use a milk replacer medicated with a coccidiostat.
- Add Corid to milk replacer (at preventative dose).
- Continue with coccidiostat until first calving.
Parasite Control Program for Dairy Cattle
Weaning to First Calving (~24 months):
Housing types:
Group pens with dirt or concrete lot
Group lot with sparse pasture
Pasture
Parasites to control:
Coccidiosis, Nematodes, Cestodes, Ectoparasites
Control measures:
1) Manure and pasture management
2) Drugs
Trade
name |
Generic name |
Label use |
Dosage |
Precautions |
|
Ivomec |
Ivermectin |
Internal and external |
200 mcg/kg, SQ or pour-on |
Meat w/d 35 days
Milk w/d 49 days |
|
Cydectin, Eprinex |
Moxidectin,
eprinomectin |
Internal and external |
pour-on |
No meat nor
milk withdrawal |
|
Rumatel |
Morantel tartrate |
Internal |
0.44 g / 100 lbs,
mixed in feed |
Meat w/d 14 days No milk withdrawal |
Panacur or
Safe-Guard |
Fenbendazole
Paste - 10%
Feed - 0.5% |
Internal |
5-10 mg/kg, orally, paste, liquid suspension or
feed pellet |
Meat withdrawal:
Paste = 8 days
Feed = 13 days
No milk withdrawal |
|
Taktic |
Amitraz |
External |
2 gal mixed spray/adult animal |
No meat or milk withdrawal |
|
Expar |
Permethrin |
External |
0.5 oz / 100 lbs |
No meat or milk w/d, won’t get grubs |
Control Program:
Spring: Calves born in the fall - no exposure to pasture over-winter
Expar/Taktic for external parasites
Yearlings born the previous spring - any exposure to pasture
Bred heifers born the previous fall - any exposure to pasture
Ivomec/Cydectin/Eprinex or Panacur and Expar/Taktic
Heifers due to calve - any exposure to pasture
Cydectin/Eprinex or Panacur and Expar/Taktic
Fall: Calves born in the spring - any exposure to pasture
Yearlings born the previous fall - any exposure to pasture
Bred heifers born the previous spring - any exposure to pasture
Ivomec/Cydectin/Eprinex or Panacur and Expar/Taktic
Heifers due to calve - any exposure to pasture
Cydectin/Eprinex or Panacur and Expar/Taktic
Adult lactating cows:
Housing type:
Complete confinement - Expar/Taktic spring and fall as needed.
Any pasture exposure - Spring and Fall
Ivomec/Cydectin/Eprinex or Safe-Guard/Rumatel and Expar/Taktic
Additional Fact Sheets:
-Control of Equine Parasites – R.D. Scoggins, DVM, University of Illinois
-Control of Internal Parasites in Sheep – R.D. Scoggins, DVM, University of
Illinois
-Control of Parasites in Grazing Beef Cattle - G. L. Meerdink, DVM,
University of Illinois
Project funding provided by: North Central Region Sustainable Agriculture
Research and Education Program
Project coordinated by: Dean Oswald, Animal Systems Educator, Macomb
Extension Center, 480 Deer Road, Macomb, IL, 61455.
The U.S. Department of Agriculture (USDA) prohibits discrimination in
all its programs and activities on the basis of race, color, national
origin, age, disability, and where applicable, sex, marital status,
familial status, parental status, religion, sexual orientation, genetic
information, political beliefs, reprisal, or because all or a part of an
individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities
who require alternative means for communication of program information
(Braille, large print, audiotape, etc.) should contact USDA's TARGET
Center at (202) 720-2600 (voice and TDD). To file a complaint of
discrimination write to USDA, Director, Office of Civil Rights, 1400
Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800)
795-3272 (voice) or (202) 720-6382 (TDD). |
|
Download
This Factsheet
PDF |
 |
Animal
Health
Control
of Parasites in Equine
Illinois
|
By: R. D. Scoggins, D.V.M., Extension
Veterinarian,
University of Illinois College of Veterinary Medicine
Administration:
How an anthelmintic is administered has little bearing on its
effectiveness. IN GENERAL, as long as the following criteria
are met, regardless of the route of administration (stomach tube,
intra-oral, or mixed with feed), effective deworming should occur:
1. The correct amount of dewormer must be administered based
on an accurate estimation of the horses weight.
2. Dose consumption and/or retention must be complete.
3. The anthelmintic selected must be highly effective against
the parasites infecting the horse.
4. The anthelmintic must be approved for use via the route of
administration selected.
Adults:
In most cases, six dewormings yearly aimed at strongyle control
are the framework for a complete interval deworming program (table
1).
Bot infestation: Boticides should be administered at least two
times per year. Once about one month after the first bot egg
is noticed on the hair coat of horses, and once after the end
of the botfly season.
Foals:
Interval deworming programs for foals should include six dewormings
at 2 month intervals beginning at 8 weeks of age. Routine anthelmintic
therapy is begun at 8 weeks of age, because that is when immature
and mature adult stages of P. equorum are commonly first present
in the small intestine (table 2).
Tapeworm Control:
Some beneficial control of tapeworms can be achieved with the
manufacturers recommended dosages of pyrantel pamoate (6.6
mg/kg). Better control can be achieved with double the label
dosage of pyrantel pamoate (13.2 mg/kg). Benefit from treatment
can be optimized by treating 2 weeks prior to and at the conclusion
of the grazing season.
Environmental Control:
Additional parasite control beyond that achieved by routine administration
of anthelmintics may be obtained by implementing management practices
that further decrease the number of infective stages of parasites
in the environment. Management practices that enhance parasite
control include the following:
1. Routine removal of feces from stalls, pastures, and paddocks.
2. Proper disposal of manure. Manure SHOULD NOT be spread on
pastures unless it has been composted for over one year.
3. Regular rotation of pastures and avoidance of overstocking.
4. Quarantine all new additions. Have fecal examinations conducted
and use appropriate treatment with non-benzimidazole anthelmintics
before intermingling with other horses.
5. Prevention of fecal contamination of feed and water.
6. Harrowing pastures during the driest and hottest season of
the year.
7. Deworm all horses housed together at the same time.
8. Have fecal examinations performed regularly to evaluate parasite
control (10-14 days following treatment).
Table 1: Example of an interval deworming program for adult horses in the North Central United
States.
|
Month |
Anthelmintic |
Efficacy |
|
February |
Pyrantel pamoate |
Nematodes |
|
April |
Oxibendazole |
Nematodes |
|
May |
Fenbendazole &
Piperazine |
Nematodes |
|
July |
Ivermectin |
Nematodes and Bots |
|
September |
Pyrantel pamoate |
Nematodes |
|
November |
Ivermectin |
Nematodes and Bots |
Table2:
Example of an interval deworming program for foals with an average birth date in February
in the North Central United States.
|
Age (Months) |
Anthelmintic |
Efficacy |
|
2 |
Ivermectin |
Nematodes |
|
4 |
Oxibendazole |
Nematodes |
|
6 |
Pyrantel pamoate |
Nematodes |
|
8 |
Ivermectin |
Nematodes
& Bots |
|
10 |
Pyrantel pamoate |
Nematodes |
|
12 |
Ivermectin |
Nematodes
& Bots |
Table 3. Example of a seasonal deworming program for adult horses in the North Central United
States.
|
Month |
Anthelmintic |
Efficacy |
|
May |
Ivermectin |
Nematodes |
|
July |
Ivermectin |
Nematodes &
Bots |
|
December |
Ivermectin |
Nemoatodes &
Bots |
Additional Fact Sheets:
-Control of Parasites in Grazing Beef Cattle - G. L. Meerdink,
DVM, University of Illinois
-Control of Internal Parasites in Sheep R.D. Scoggins,
DVM, University of Illinois
-Control of Parasites in Dairy Cattle Dick Wallace, DVM,
MS, University of Illinois
Project funding
provided by: North Central Region Sustainable Agriculture Research
and Education Program
Project coordinated
by: Dean Oswald, Animal Systems Educator, Macomb Extension Center,
480 Deer Road, Macomb, IL, 61455.
The U.S. Department of Agriculture (USDA) prohibits discrimination in
all its programs and activities on the basis of race, color, national
origin, age, disability, and where applicable, sex, marital status,
familial status, parental status, religion, sexual orientation, genetic
information, political beliefs, reprisal, or because all or a part of an
individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities
who require alternative means for communication of program information
(Braille, large print, audiotape, etc.) should contact USDA's TARGET
Center at (202) 720-2600 (voice and TDD). To file a complaint of
discrimination write to USDA, Director, Office of Civil Rights, 1400
Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800)
795-3272 (voice) or (202) 720-6382 (TDD). |
|
Download
This Factsheet
PDF |
 |
Animal
Health
G. L. Meerdink, DVM - Veterinary Diagnostic Lab
& Extension University of Illinois
|
Bloat or ruminal tympany is the abnormal extension of the
rumen and reticulum caused by excessive retention of the gases of
fermentation. Rumen gasses separate from the rumen contents and the gas
pocket is eliminated by eructation (belching). Normally, eructation can
remove much larger quantities of gas than produced at the maximum rates of
fermentation. Therefore, bloat does not occur because of excessive gas
production but rather from insufficient elimination.
Causes of bloat include:
• Nerve receptors surrounding the entrance into the
rumen from the esophagus, the “cardia region,” detect the presence of gas
and allow gas release–eructation. If fluid or foam (as in frothy bloat)
contacts the cardia region, it remains firmly closed. Thus, rumen gas
accumulates.
• Frothy bloat is usually related to highly digestible
plants, especially legumes. Soluble leaf proteins and plant particles
readily produce a stable foam-like material that obstructs the cardia and
restricts eructation. Reducing foam and freeing the gas for release is
difficult.
• Ruminal contractions are essential for eructation.
Therefore, any injury to the nerves of the rumen or other disruptions of
rumen activity can result in bloat.
• Cattle that are down for an extended time can bloat
because the cardia is covered with fluid that prevents eructation.
Eructation occurs when the animal stands or roles up on the sternum after
the fluid moves away from the cardia.
• Feedlot cattle on high concentrate diets might have
some bloat problems related in part to reduced rumen motility. Also, some
bacteria (that can proliferate in high concentrate rumen environments) are
thought to produce a slime, resulting in a stable foam which impairs
eructation like a frothy bloat.
Observations:
• Bloat incidence decreases when legumes begin to
flower (probably due to reduced digestibility).
• Bloat is reduced when grazing is continuous and not
interrupted.
• The bloat potential for legumes is not necessarily
lost after a killing frost. Pasture bloat is more likely during the spring
and other times when plants are young, succulent and have higher
digestibility.
• It is safer to move cattle to a new pasture in the
afternoon (after the dew has dried) with a rumen fill from the former
forage.
• Forage maturity is a major plant factor affecting
the incidence of pasture bloat. Grazing very succulent pasture, such as
immature legumes in the pre-bloom stage, is the single biggest risk of bloat
in cattle.
• Bloat onset may be observed within an hour after
introduction to new pasture. However, cattle more commonly bloat on the
second or third day (or longer) following introduction.
• Although acute death in the feedlots is unusual,
mild bloat can affect performance.
• Generally, feedlot bloat is delayed which
corresponds with the development of a suitable rumen environment for gas
entrapment.
Treatment:
• Removal of free gas can be done with passage of a
stomach tube use of a trocar or large gauge needle inserted directly into
the rumen high on the left side at the point of maximum distension. (Rumen
penetration through the skin is usually avoided because of the chance of
infection and peritonitis.)
• Frothy bloat is a challenge because the stomach
tube, or trocar, are quickly plugged by the foamy material. (If time is of
the essence, an emergency rumenotomy (surgical opening of the rumen) may be
necessary to save the animal’s life.)
• Anti-foaming agents such as non-toxic oils,
detergents or surfactants can be used to decrease the surface tension and
break down the foam to larger gas bubbles that can be removed with stomach
tube or eructated. Polaxalene® is faster and more effective than oils and is
recommended for treatment. (This may be of little value for feedlot or grain
bloat.)
• Saliva is important in the prevention/reduction of
bloat. Tying a stick in the mouth like a horse’s bit has been used to
promote saliva production. The alkalinity of saliva may assist in
denaturation of the stable foam. Careful drenching with about 100 to 150
grams of baking soda (sodium bicarbonate) in water might accomplish the same
end.
• Mildly bloated feedlot cattle (“swellers” or
“tight”) might respond to walking, which can shake the foam down and
coalesce the foam into a large bubble that can be expelled.
• In any event, the treatment approach will depend on
the degree of animal distress. This condition can kill quickly.
Prevention:
• Pasture bloat is unpredictable and difficult to
prevent. A host of strategies have been tried to prevent the problem. The
objective is to decrease the rate of rumen fermentation (which contributes
to foam that prevents eructation). No one strategy works consistently, but a
few ideas include:
• Don’t turn hungry cows into lush alfalfa. Fill them with dry hay
before turning them out.
• Restrict grazing time or pull cows from pasture when the first cow
stops eating.
• Do whatever is necessary to make the change to new forage as gradual
as possible.
• Turn cattle out after dew is gone; wait until afternoon when forage is
dry.
• Don’t remove cows at the first sign of bloat. They’ll adapt if left on
the pasture.
• Bloat often occurs with warm humid weather following a rain. The
fast-growing tips of legume plants contain agents that promote the
production of froth.
• Seed pastures with grass-legume mixtures.
(Because of selective grazing, this surely does not guarantee prevention.)
• Oils and fats and bloat preventative agents such as
Polaxalene® (i.e. Bloat-Guard™) certainly help in prevention. The challenge
is getting enough into the animals at the time needed. (Individual dosing
with liquids or capsules or flank application prior to turn-out has been
successful.)
• Ionophores (e.g., Rumensin® and Bovatec ®) aid in
the reduction of bloat.
The U.S. Department of Agriculture (USDA) prohibits discrimination in
all its programs and activities on the basis of race, color, national
origin, age, disability, and where applicable, sex, marital status,
familial status, parental status, religion, sexual orientation, genetic
information, political beliefs, reprisal, or because all or a part of an
individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities
who require alternative means for communication of program information
(Braille, large print, audiotape, etc.) should contact USDA's TARGET
Center at (202) 720-2600 (voice and TDD). To file a complaint of
discrimination write to USDA, Director, Office of Civil Rights, 1400
Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800)
795-3272 (voice) or (202) 720-6382 (TDD). |
|
Download
This Factsheet
PDF |
 |
Animal
Health
G. L. Meerdink, DVM - Veterinary Diagnostic Lab
& Extension University of Illinois
|
Ergot is associated with the fungus, Claviceps sp., which
infects a variety of grasses, notably the cereal grains. Ergot bodies are
the black-purple bodies (similar in appearance to rat droppings) that form
in place of a seed in grass heads. See Figure 1. (Grasses take up the mold
spores from the soil and are transported to the seed heads. Ergot bodies
develop and drop to the ground for the next generation.) These bodies
contain a number of alkaloids, referred to as ergot alkaloids, that affect
blood vessels, the nervous system, and other organ systems.
Ergot alkaloids are the same toxic agents found in endophyte-infected
fescue.
What does this do to cattle?
• Some of these alkaloids are capable of
constricting blood vessels. The result is dry gangrene of the extremities:
feet, tail, and ear edges.
• Lameness is generally the first sign, along with
swelling around the fetlock area. Back legs are usually first affected.
Swelling and pain becomes severe followed by sloughing of skin and
eventually the foot is sloughed above the hooves. This disease has been
called “fescue foot.” (Figure 2.)
• Fescue foot is more common during winter, most
likely because low temperatures contribute to decreased blood circulation.
• Decreased milk production (due to inhibition of
prolactin) is common. This can occur with no evidence of foot involvement.
• Reproduction (particularly conception) is impaired;
with severe involvement, calving can be impaired.
• With milder cases, the loss of switch hair from the
tail and, perhaps, the edges of ears can occur.
• Though more associated with fescue, these alkaloids
disturb the animal’s heat regulation that is associated with the “summer
slump” syndrome.
Prevention:
• Clip pastures to restrict grazing of grass heads.
• Clipping fescue pastures is especially important
since the endophyte-infected grass also contains some of the same alkaloids.
• Ergot bodies and toxins survive baling and ensiling.
If baled with grass heads, collect chaff by shaking hay into a plastic bag
and look for the ergot bodies. If present, feed sparingly (if at all). Avoid
feeding contaminated hay during the winter.
• Providing shade during summer and supplementing some
grain, especially during breeding, seems to reduce effects somewhat.
• Ammoniation of contaminated hay has been found to
reduce toxic effects; as yet, the degree of success with this on
ergot-contaminated forages has not been determined.
Figure 1. Several different grass varieties infected with black ergot
bodies.

Figure 2. This calf was one of several with sloughed hooves. They were fed
large round bales of brome grass infected with ergot.

The U.S. Department of Agriculture (USDA) prohibits discrimination in
all its programs and activities on the basis of race, color, national
origin, age, disability, and where applicable, sex, marital status,
familial status, parental status, religion, sexual orientation, genetic
information, political beliefs, reprisal, or because all or a part of an
individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities
who require alternative means for communication of program information
(Braille, large print, audiotape, etc.) should contact USDA's TARGET
Center at (202) 720-2600 (voice and TDD). To file a complaint of
discrimination write to USDA, Director, Office of Civil Rights, 1400
Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800)
795-3272 (voice) or (202) 720-6382 (TDD). |
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Animal
Health
G. L. Meerdink, DVM - Veterinary Diagnostic Lab
& Extension University of Illinois
|
Pinkeye (or Infectious Bovine Keratoconjuctivitis) is caused
primarily by Moraxella bovis along with a number of inciting factors.
Because of the pain involved and potential for blindness, this is an
economically important disease to prevent. Estimates indicate approximate
weight losses of about 20 lbs. With the loss of one eye and at least 65 lbs.
in calves over a 205 day period. Loss in milk production, labor, medication
and loss in value are additional economic losses.
Observations
• Although M. bovis is considered the primary
causative agent, a number of other infectious agents (e.g., IBR virus,
Mycoplasma, Chlamydia, etc.) can affect severity and incidence in the herd.
Young animals are more sensitive.
• Source of the organism is from carrier animals. The
organism overwinters in the eye, nose, and vagina of some animals.
• Solar radiation, flies and dust, or anything else
that causes eye irritation, play significant roles in the severity and
incidence rate of the disease.
• Flies are significant transmitters of the organism.
(Pinkeye incidence of 14% has been measured with 6-10 flies/head and 26% was
related to 16-20 flies per head.
• Pinkeye in calves is enhanced by eye irritation from
tall pasture grasses and seed heads.
• Though usually a warm, humid, summer problem,
outbreaks do occur in winter and can be severe.
• Incidence and severity is probably less with
increased pigmentation around the eye.
• Virulence (disease-evoking severity) is enhanced by
solar radiation. Outbreaks seem to be associated with periods of maximum
solar UV radiation.
• Nutritional deficiencies (vitamin A, iodine, etc.)
influence incidence and severity.
Disease Signs
• Tearing and blinking are the first signs of
pinkeye. Pain and sun sensitivity is significant.
• Conjunctiva (tissues around the eye) are red and a
white spot can eventually be seen on the cornea (center of the eye).
• The white spot on the eye is an area of dying
tissues that eventually results in rupture of the eye associated with loss
of sight and a great deal of pain.
Treatment
• Treatment at the first signs is critical. In just
a few days, irreversible blindness can occur.
• An eye patch or surgical eyelid closure to block
sunlight aids recovery and reduces pain.
• Several antibiotics are usually effective and
different methods of administration are possible. Contact your veterinarian
for best selection and administration method.
• Resistant strains do occur. If there is a poor
response to treatment, samples should be collected for culture
identification and antibiotic sensitivity tests.
• If treatment response is not noticed in 24-48 hours,
contact your veterinarian. Different strains or other immunological factors
can alter therapeutic methods and vaccine response. Prevention
• Vaccines are generally beneficial, but responses
are variable. Results are compromised if administered too late. Two doses (3
weeks apart) administered before fly season are needed. Consult with your
veterinarian regarding the best choices for your region.
• Because of strain differences, an autogenous
(vaccine made from the culture from your herd) might be necessary.
• Control flies. A host of control programs are
available. Dragging pastures to disrupt manure pats retards fly reproduction
and reduces populations somewhat.
• Maintain a strong herd immunity against IBR with
routine vaccination.
• Optimize nutrition status, including minerals.
Supplement vitamins A & E in animals accustomed to a poorer quality hay diet
and during winter.
• Clip pastures to reduce eye irritation for young
calves.
• Shade helps reduce the solar radiation that enhances
development of the disease.
• Treat diseased eyes as quickly as possible to
prevent permanent eye damage, weight loss, and reduce transmission of the
causative agent to others.
• Separation of affected animals has been advocated.
However, the benefits are questionable since infected flies travel
appreciable distances.
The U.S. Department of Agriculture (USDA) prohibits discrimination in
all its programs and activities on the basis of race, color, national
origin, age, disability, and where applicable, sex, marital status,
familial status, parental status, religion, sexual orientation, genetic
information, political beliefs, reprisal, or because all or a part of an
individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities
who require alternative means for communication of program information
(Braille, large print, audiotape, etc.) should contact USDA's TARGET
Center at (202) 720-2600 (voice and TDD). To file a complaint of
discrimination write to USDA, Director, Office of Civil Rights, 1400
Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800)
795-3272 (voice) or (202) 720-6382 (TDD). |
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Animal
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Illinois
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General Information
We, as producers and technical specialists, try to focus on providing
information to the livestock clients on how to improve the quantity and
quality of the forages, produced and consumed, for the livestock to improve
performance and gains. First we should look at the definitions of both
Quality and Anti-Quality Factors.
Forage and Nutrition
“Forage quality can be defined as the degree to which forage meets the
nutritional requirements of a specific kind and class of animal. An
‘anti-quality component’ would, therefore, be any factor that diminishes the
degree to which forage meets the nutritional requirements of a specific kind
and class of animal.” 1
This is further complicated by the animal types and the various growth and
production stages of the animals at different periods of time in their life
cycle. The anti-quality components can vary in both kind and class in the
plants. The two types are phytochemicals in plant tissues or structural
inhibitors in leaf and stem arrangements. These can result in mineral
deficiencies, toxicities, or mineral deficiencies. Chemical inhibitors can
result from plant metabolism or from microbes living in the plants. Other
anti-quality factors in forages can be related to the presence of insects
and diseases. Any anti-quality factor can reduce dry matter intake, limit
dry mater digestibility or cause nutritional imbalances. These same factors
may also be toxins that shut down vital systems in animals, resulting in
abnormal reproduction, disturbed endocrine or neurological function, causing
genetic aberrations, or suppressing immune function leading to increased
death and diseases.
“The study of these anti-quality factors is both complex and compelling
because of the many and unrelated causes and yet potential for many
interactions and subtle interrelationships.” 1
Economics
If we look at the economic impacts from anti-quality factors, these can
have the potential to be very expensive to a livestock operation. “Tall
fescue toxicity has been estimated to cost the beef industry over $600
million annually. Reproductive and death losses of livestock to poisonous
plants have been estimated at $340 million in the 17 western states alone.”
1 Other imbalances in forages can occur such as magnesium deficiency,
reported to inflict a loss ranging from 1-3% for beef cows annually. This
could be equivalent to $150 million in the U.S. if only 1% of the 42.6
million cows and heifers that calved by January 1, 1999, weighing 1100 lb.
per cow, and were valued at $0.35 per lb. The fescue toxicosis can have a
long lasting and measurable effect on the animals throughout the stress of
cross country transportation and throughout a 150 day feeding period. It can
also effect livestock production by lowering the immunity of an animal and
cause higher medication costs.
Poisonous plants can occur in any rangeland and pastureland area. These can
be one of the most important economic impediments to profitable livestock
production. “Based on an estimated 1% death loss in cattle, a 3.5% death
loss in sheep, and a 1% decrease on calf and lamb crops due to poisonous
plants, the economic impact within the 17 western states had been estimated
at $340 million annually.” 1 These are only a few of the areas the
anti-quality factors can have an impact. Low forage quality that can reduce
gain performance is another large contributing factor in the economic
picture of an operation. Thus, if we all look at the importance in forage
testing for feed values and mineral content, we may improve our operation’s
bottom line. Also, the species identification within our grazing areas can
save us several dollars by utilizing the forage at the proper time and
eradicating potential hazardous plants. Some of these poisonous plants tend
to grow in shaded areas; thus restricting livestock use in shaded areas may
be an easy control mechanism to avoid animal access.

References
1 Quotes are taken from Station
Bulletin 73 July 2001 prepared by USDA/NRCS Grazing Lands Technology
Institute, Idaho Forest, Wildlife and Range Experiment Station Moscow, Idaho
and University of Idaho. Figure 1 from Station Bulletin 73, July 2001,
prepared by USDA/NRCS Grazing Lands Technology Institute, Idaho Forest,
Wildlife and Range Experiment Station, Moscow, Idaho and University of
Idaho.
Prepared by
Roger L. Staff, Grass Land Specialist, NRCS
The U.S. Department of Agriculture (USDA) prohibits discrimination in
all its programs and activities on the basis of race, color, national
origin, age, disability, and where applicable, sex, marital status,
familial status, parental status, religion, sexual orientation, genetic
information, political beliefs, reprisal, or because all or a part of an
individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities
who require alternative means for communication of program information
(Braille, large print, audiotape, etc.) should contact USDA's TARGET
Center at (202) 720-2600 (voice and TDD). To file a complaint of
discrimination write to USDA, Director, Office of Civil Rights, 1400
Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800)
795-3272 (voice) or (202) 720-6382 (TDD). |
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Animal
Health
lG. L. Meerdink, DVM - Veterinary Diagnostic Lab
& Extension University of Illinois
|
General Information
Neospora caninum is a very common protozoal organism and a common cause
of abortion in cattle. Minor reductions in milk yield in dairy cows or
reduced growth in feedlot steers has also been attributed to this organism,
but these effects, if true, are small. A reasonable goal of herd management
is to reduce the risk of transmission of neospora. Total elimination is
unrealistic. A depiction of the neosporosis life cycle follows.
Observations
• Dogs, and other canines, e.g., coyotes, become infected by eating
tissues of infected animals. Infected dogs shed oocysts in their feces for
about 1 week. • Oocysts can survive in the environment for a long time.
• Once a cow is infected, she probably remains infected for life.
• Many, probably most, infected cows never abort and can be excellent
producers. • Neospora is transmitted to cattle in different ways:
• A chronically infected cow can transmit the organism during pregnancy to
her fetus. (vertical transmission) • Cattle can become infected by ingesting neospora oocysts that have
contaminated pastures or feedstuffs from the feces of infected dogs, or
other canines. (horizontal transmission) • Heifers born with neospora infections (congenital, from dam during
gestation) are more likely to have an abortion during the first pregnancy
than are heifers that were born uninfected (and that remain uninfected).
• This method of disease transmission is believed to be associated with the
larger herd outbreaks of abortion. • 40-50% of Illinois white-tailed deer have a positive blood test. Though
dogs and other canines can become infected by eating the infected tissues,
deer cannot directly transmit neospora to cattle.
Prevention Control
• Prevent dogs (coyotes, etc.) from defecating in stored feeds intended
for breeding cattle. • Some examples include: use containment facilities (silos, bins, etc.);
close feed storage doors; cover bunker silos; dog and coyote-proof fence
feed storage areas. • Cattle are more likely to consume dog feces if feed is mixed (i.e., TMR).
• Restrict canine access to dead stock (including placentas).
• Limit the number of dogs. (The prevalence of infected cattle is
statistically associated with both the presence and number of dogs.)
• Generally, culling cows based on serologic (blood) testing for neospora
antibody titers is not recommended. • Chronically infected cows have a measure of immunity. Previously infected
cows have a decreased risk of abortion compared to acutely infected cattle
during neosporosis abortion outbreaks. • The titer cut-off between serum-negative and serum-positive cows is not
perfect and the neospora antibody titer in any particular cow can fluctuate
above and below cut-off level. • In herds with a chronic neosporosis abortion problem, selection of serum
negative replacement heifers can speed the rate of reduction of neospora-infected
cattle. • Blood-test replacement heifers anytime after six months of age and keep
only negative animals, or keep only heifers born to serum negative cows.
(This strategy must be accompanied by practices to reduce the risk of
transmission from dogs. • Vaccination
• To date, no independent reports of the product’s efficacy have been found.
Thus, a recommendation at this time is questionable. •
Two doses are required the first year it is used.
• Serum tests for the Neospora antibody do not distinguish the difference of
vaccination from natural infection. • Pasture treatments will not affect the likelihood of exposure to the
organism. This is an unlikely source of infection for large numbers of
animals. • Testing the farm dog is of little value. Not all dogs will be serum
positive after infection and the period of shedding of oocysts subsides
within a few weeks.

Acknowledgements
Milton McAllister, DVM, PhD, College of Veterinary Medicine, University
of Illinois.
The U.S. Department of Agriculture (USDA) prohibits discrimination in
all its programs and activities on the basis of race, color, national
origin, age, disability, and where applicable, sex, marital status,
familial status, parental status, religion, sexual orientation, genetic
information, political beliefs, reprisal, or because all or a part of an
individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities
who require alternative means for communication of program information
(Braille, large print, audiotape, etc.) should contact USDA's TARGET
Center at (202) 720-2600 (voice and TDD). To file a complaint of
discrimination write to USDA, Director, Office of Civil Rights, 1400
Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800)
795-3272 (voice) or (202) 720-6382 (TDD). |
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Animal
Health
Diseases
Illinois
Being Developed |
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Animal
Health
Toxicities/Poisoning
Illinois
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