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Preventing diseases
in
your stock
It costs a little bit of money, and may take a little time.
Afterwards you’ll have the reassurance that your animals won’t get the diseases
you’ve protected them from..
You be able to achieve your plans:
Healthy stock for selling, breeding, petting, or for the deep freeze.
You’ll gain financially for your efforts.
Manufacturers make it easier for you:
Some products are designed to prevent several diseases in the one product.
Sometimes the manufacturers add vital minerals to the “dose”. (Selenium is a
common additive.)
Treat your stock when they are healthy.
*There are “best time (s) of the year” or “Stage of the animal’s life” when
treating is recommended. i.e. The time when drenching, or vaccinations will
achieve the maximum results.
Your local vets are the experts.
Nitrate poisoning:
New grass has the potential to cause nitrate poisoning:
New Zealand:
http://www.teara.govt.nz/en/diseases-of-sheep-cattle-and-deer/10/2
Australia:
http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0006/111003/nitrate-and-nitrite-poisoning-in-livestock.pdf
Internal
Parasites: Drenches, &
Management..
Do you need to drench?
The answer is in your animals dung.
Fresh dung samples collected from your animals,
can be viewed under a
microscope..
This count of eggs and larvae in your animals dung is referred to as a: Faecal
Egg Count (FEC), or "worm
test".
In New Zealand these can be arranged through your local vets..
Other countries:
Type in “FECPAK” or faecal egg count, on a "Your country” search engine.
Don’t
be shy of
faecal egg counts:
They’re such a valuable tool. In fact; they could save you money!!
You’re stock will benefit from the information obtained from these dung samples.
Faecal egg counts will:
Identify your parasites, and the parasitic burden.
They will indicate IF you need to drench.. or not.
They can be used to check the effectiveness of your drench.
..
Drench resistance is a serious, and common world wide problem.
Testing for the effectiveness of the drench
involves:
1.
A faecal egg count is done prior to drenching. This tells you what worms you have
2.
After drenching (about a week later) collect samples of faeces..
If the drench is
effective there should be NO worms in the samples.
Do ask your local vets for advice if you suspect there could be drench
resistance.
*Many stock do have worms in their digestive system, and basically it’s normal.
Exposure to the worms enables the animal to build up immunity. (This is why older stock are often resistant, and
younger stock are vulnerable.)
Healthy looking animals are not necessarily “parasite free” .-They could be “sub-clinical”:
(“Sub clinical” refers to any disease (veterinary and medical) where, because
the disease is mild, the symptoms do not show.
It could mean their worm population is too low for clinical signs to be
obvious. They will contaminate the pasture with eggs and larvae when they
"relieve themselves".
The larvae that the animal has ingested may not have developed yet.
-The animal may be tolerating the parasite load it's hosting, or it is resistant to that type
of worm.
-Although you’re animals may look healthy, you may have missed some clues: eg:
Not gaining weight.
Or a very gradual weight loss.
It is wrong to presume that a scouring animal (or the one with a “dirty bottom”)
has worms.. Scouring could be due to a totally different reason.
Stock susceptibility
to
parasitic diseases:-
Most internal parasites are specific to 1 or 2 species.
Older animals are often resistant to parasites.
Grazing habits:
Sheep are most susceptible to internal parasites because of the way they graze:
i.e. close to the ground.
Goat and sheep will above the manure deposited.. Cattle avoid eating near dung
deposits.
Your young stock:
They're young and they have NEVER been exposed to the larvae
previously.
They’re young and growing, and they need protection.
Young stock need the best of everything. They DON’T need setbacks
at this young stage of their life.
It is common to drench young stock at weaning.
Older stock has had the opportunity to build up some immunity/resistance.
Stressed, and poorer animals:
Poor weather, pregnant and lactating animals, feed shortage, and less
healthy animals. This group are more susceptible to parasites. In other words
your animals are better able to resist internal parasites when there is abundant
feed, and conditions are good. It may pay to check on mineral deficiencies also.
New animals on your farm:
There is a possibility that they may have NEVER experienced the type of worms
you have on your farm…
Or: They are bringing worms to your farm.
These could be worms that could be resistant to the drench you are using.
(Quarantine new animals, and drench them with a quarantine drench.(ask the vets)
Keep them away from other stock for several days until the stock have “passed”
any egg laden dung.
Grazing other peoples stock, or grazing your stock off the farm:
An arrangement to minimize parasite spread needs to be part of the:
GRAZIER-ANIMAL OWNER CONTRACT.
The arrangement may take into consideration.. the season…the length of time
animals are grazed out, the usual animals on the graziers farm (sheep.. cattle
..goat) and even the suitability of the graziers yards for drenching your stock.
Stock effectively drenched prior to them leaving the “home farm” will not be
contaminating the graziers farm..
There is always the possibility that your stock could bring drench resistant
worm’s home.
Drench
Resistance is a
HUGE
problem.
What is it.?
Farmers have been drenching their stock for parasites for years.
Over the years parasites have "adapted" to drenches. That once effective drench family no
longer kills parasites that have “adapted”. These parasites are now
resistant
to that drench family. (i.e. the drench family no longer "work" on those
parasites.)
WORSE STILL:
These “Drench resistant parasites” have passed their genes on to
the next generation of parasites, and then on to the next, and to the next, and
so on.
There are so MANY Drench resistant parasites, and it is now a serious world wide
problem.
If the worms; (those in the paddock, and those hosted by your animals) are
resistant to the drench family you are using then:
Your drench will:
Kill susceptible worms only.
It will not kill the many resistant worms, and your stock will still be
contaminated.
They continue to spread those drench resistant worms in their dung.
They will ingest more drench resistant larvae when they graze the drench
resistant larvae laden pastures.
(It’s a serious problem, and it can easily go unnoticed.)
An animal that was once sub-clinical may exhibit the clinical characteristics of
the parasitic disease, when the parasite burden increases.
BUT.. because she has been continually expelling the eggs/larvae, sharing the l
This will continue until you change your drench family.
~
Check
out these helpful web sites:~
.New
Zealand site
-Drench resistance
can lead to drench failure. but active worm management can help ...
find out the drench resistance status of your farm and ...http://www.maf.govt.nz/sff/whats-on/managing-worms-update-115-feb06.pdf
Australian sites.
-In
flocks where the development
of drench
resistance has altered the control ... Drench resistance is
the failure of a drench, when administered at the ...http://www2.dpi.qld.gov.au/sheep/4691.html
-WORMS
IN GOATS:
http://kakadu.nt.gov.au/pls/portal30/docs/FOLDER/DBIRD_PI/ANIMALS/
PUBLICATIONS/ANIMAL_DISEASES/AGNOTE+625+K5.PDf
United Kingdom sites.
-A recent UK survey
showed
evidence of white drench resistance on. 80 % of Lowland; 55 % of Upland
and; 45 % of Hill sheep farms ...http://www.iger.bbsrc.ac.uk/Practice/Publications_&_Leaflets/informationsheets/InternalParasites.htm
-Anthelmintic
Resistance
in Roundworms and Improved Drenching Techniques ... The Production
& Health of Farmed Deer, The Six Key Areas That
Must Be Addressed ...http://foundation.mri.sari.ac.uk/disease-summaries.asp?ref=1
Anthelmintics /
Drenches /
Parasiticides~
Anthelmentics:
Kill parasites in the hosts body. The dead parasites are then expelled from
the host’s body.
In the animal’s body:
It is absorbed into the animal’s bloodstream where it is distributed around the
body.
later it is broken down in the liver, and excreted in the animals urine and faeces.
Be aware: That some drenches may have specific instructions e.g. Not to be used
on animals in the early stages of pregnancy.
The Drench Families:
Bendimidazoles / The White drenches:
These drenches have been around for years.
They rapidly kill, and are very effective against the worms in the host’s
digestive system.
Their ability to “kill” is short lived, so a follow up drench is required.
Action: They deprive the parasites of their food supply, and they starve
to death.
Pregnant animals: Do read the labels on the container as some while drenches
should not be use on pregnant animals.
Levamisole/ The Clear drenches:
The best time to use these drenches is when your stock are first weaned.
Levamisole is active against many bendimidazole-resistant parasites.
They won’t however kill the ostertagia larvae that have already imbedded
themselves in the abomasum wall.
In Autumn the larvae/worm population is the highest, so other drenches should be
used.
Action: These drenches paralyze the worms. They are then digested, and
destroyed by the host.
Excretion from the body is rapid, and therefore the withholding period is
shorter.
Endectocides /Avermectin/Ivermectin /Third generation drenches”
These Third generation drenches are effective against most types of worms.
These drenches remain active in the body for several weeks, so the
withholding/withdrawal time is much longer.
Action: Theses drenches paralyze the the parasites. They are then
dislodged and excreted.
The follow up drenching interval is also longer.
They are more expensive.
Ineffective against tapeworm and liver fluke.
A Broad Spectrum drench: This basically refers to the drenches ability to kill
several varieties of parasite.
Presently the recommendation is: Use the one drench family for one year..
Change to another drench family the following year.
IT IS recommended that you work out a drench plan with your local vet.
Farmers have reported:
That their animals actually “do better” after they’ve been drenched.
Do
consult your
“RURAL” or
“BIG
ANIMAL” VET.
A drench that suits one species of animal may not suit another species. (Goats
in particular)
Your local vets have the “inside and outside” knowledge of your type of farmed
animal, the district, and your climate.
They’re also aware of soil deficiencies in your local soils. The nutrients that
are beneficial to your animals health.
Vets can arrange tests:
A *faecal egg count, & any blood tests, or biopsies ect.
They’ll help you work out a drench plan for your stock.
Drenches can be administered in different ways.
 By:
Mouth (oral), applied to the skin/hair (pour on) or by injection, or as a
slow release bolus.
You can ask the vets all sorts of questions about drenching technique.
For small scale farmers who need a small quantity of drench for their animals the
Vet’s are the most likely to sell to you only the quantities you need.
Your vets may have equipment available to purchase.
Subcutaneous Injections: (SC, or SCI)
These are given under the skin...and above the tissues beneath the skin.
The skin needs to be pulled up.. ("bunched up".. or "tented")
The needle is injected into the "gap" between the 2 layers.
These are usually given under the skin in the region behind the ear.
Make sure there is no air in the syringe when giving an injection.
Withholding period /Withdrawal time:
After drench administration there is a period of time until the drench is
“broken down” and is excreted.
This period of time is the “withholding period”/”withdrawal time”.
Any time within the withholding period the animal cannot be used as meat, and
possibly milk.
*Check if the drench is safe to use on animals providing milk for human use.
The RIGHT drench, administered at the RIGHT time WILL save you money.
Reading all the information on the side of a drench container can be confusing..
Once again: If you are new to drenching, talk to your vet. You can then ask all
sorts of questions.. (Including drenching technique)
 Don’t be tempted:
< to buy a product because they promise a freebe with the
purchase.
Before using Drench guns:
Check that it is working ..(And give it a thorough clean at the same time)
Check it for accuracy (very important) Gently squirt a measured amount into a measuring
container.
Wash the drench gun out after use so it’s ready for next time.
SEE:
www.ermanz.govt.nz/hs/vetmed/vetmedAH.pdf
Know the
weight of your stock before you drench.
Overdosing:
Can lead to toxicity.
Under dosing:
Will mean ineffective treatment.
A “tape weight” measure will give a “guide” to the animal’s weight.
For smaller animals:
Make use of the “bathroom” scales.
This will involve holding the animal while you step in the scales. Deduct your
weight from the total weight.
If the herd/flock is all about the same size:
Calculate the amount of drench required by the weight of the largest animal.
With mixed sized animals:
You’ll need to put them into groups according to their size.
Drench according to the weightiest animal in each group.
* Drench all the animals in the group.
Those Parasites..
Their Life cycle:
Parasites use a host animal for their nourishment and spread.
An animal infected with a parasite (ie the host) will excrete either eggs or
very early larvae in its dung.
In dung they mature into larvae.
As larvae they’ll move up a grass blade, ready
to be eaten by stock.
There are several stages in the egg to adult worm development.
It is in adult form that these parasites damage tissue in the host animal.
Larvae are most abundant in spring and autumn, because the weather
(dampness and
warmth) is suitable for their spread.
Animals showing clinical symptoms of the disease:
The total number of internal parasites worms that the animal is hosting
influence whether the host will show clinical signs of the disease.
With a small worm population there may be NO obvious signs or symptoms.
However the hosts total worm numbers will increase when stock continually eat
from larvae infested pastures. As the worm burden increases, so will the
likelihood of stock showing clinical signs of the disease. .
Ostertagia Life Cycle:
http://www.abdn.ac.uk/organic/organic_16b.php
Lungworm:
http://www.abdn.ac.uk/organic/organic_17.php
Description and Life Cycle of Goat Parasites:
http://personal.linkline.com/karinc/goat/parasites.html
Gastro-Intestinal Parasite For Goats:http://www.uky.edu/Ag/AnimalSciences/goats/presentations/parasitekit0104.pdf
The
Pasture,
the
Larvae
and
your
stock:
Larvae, and the weather:
Heavy rainfall can spread cattle dung, and therefore larvae can be distributed
over a larger area of pasture.
When the grass is damp (as in dew, or rain) parasites may be found further up
the blade of grass.
In dryer conditions larvae are more likely to be found near the base of the
plant. ..
Basically larvae avoid the bright sunlight.
If the weather is too hot, the eggs will hatch and die, and in very dry
conditions many larvae will be killed off.
If the weather is too cold the eggs will not hatch.
Some larvae will be killed in drought conditions.. Some larvae will be killed in
freezing conditions.
*Larvae are most abundant in spring, and especially autumn.
Hypobiosis:
Stomach worms can halt their development. (called Hypobiosis.)
They go through
this dormant stage to allow them to survive during unfavourable climate
conditions.
Larvae & the grass leaf:
Most parasite larvae live in the “bottom” couple of inches above the ground.
If you can leave 7cms or 3 inches of grass the chance of your stock eating
parasite larvae is minimized.
Sheep eat closer to the ground than cattle, and pick up more parasites.
Grass dominant pastures have a higher number of parasite larvae than other
forage.
Larvae can also be protected from the environment by safely remaining in cattle
dung.
How drench resistance happened:
Over the many years of farmers drenching to kill of parasites, some parasites
have “adapted” and have become resistant to a drench “family”.
”Use one drench family for one year, then swap to another drench family the next
year” has been standard practice for some years.. to treat stock, and to
minimize parasite resistance.
To Drench your stock:
You’ll need equipment:
(Drench gun, backpack or some method for the drench to flow into the gun. Ou may
need a vaccinator, needles ect.)
For just a few animals you could perhaps borrow the equipment.
Hire the equipment (phone the local rural hire centre to find out if they do
hire out this type of equipment)
You could purchase the equipment yourself.
Employ a contractor ..who specializes in “small farms” .. (Yellow pages)
Yards & Yarding your stock:
 If stock can be run along a narrow race, or lane, and you’re able to reach over
to drench or to vaccinate them.. this makes the task so much easier.
If you have only a holding pen, or can make up a *temporary holding pen":
* Using the corner of a paddock.. add two gates. Use binder twine around
to fasten the 2 extra gates .. so the twine also becomes a hinge. You'll then
have a: small square holding pen.
With a can of stock marker or Aerosol “tail paint” or a chalk that will show on the animal’s hair/fleece.
Mark each animal after it has been drenched. This job is so much easier if you have a
helper. !!!
<Photo from:
www.diggersvalley.co.nz.
“Lifestyle services” “Small farm services”
:
If your far too busy to drench .. look in the yellow pages of your phone book.
In some districts ex-farmers have set up a business which specialize in working
with stock owned by the “small farmers”. These farmers/workers will have the
equipment, (like portable yards, drench guns, they may also have a selection of
drenches.)
Prior to drenching:
Do you need to drench? .. Seriously consider getting a faecal egg count done.
Fecal egg counts are relatively inexpensive, and can save time and money.
Read all the instructions on the drench container.
Importantly note the length of the withholding period: (For Meat and milk)
Make a note of the drench date on you calendar.
After Drenching:
After drenching , there is merit in keeping them in the same paddock till they
have “emptied” on to that paddock.
After 12 or so hours, then let them into a “clean” paddock.
A clean paddock means a paddock with new grass, paddocks that have been used by
another species
of animal, or paddocks that have been used for hay.
Methods to reduce parasite contamination:
Drenching:
Don't neglect it..
It is standard practice
to use one drench family one year, and the following year drench using a
drench from another drench family:
Learn about the effectiveness of your drench by doing a drench effectiveness
test (faecal egg count.) Those who are using "natural methods" to eradicate
parasites on their farms.. it is recommended that a drench effectivness test be
done.
Be aware:
(Over crowding means: Too many animals for the amount of feed.)
Paddocks overcrowded with stock will increase
the concentration of parasites.
Roughly 80%of parasites live in the first 5cm of pasture..
When a paddock is over crowded, animals will be forced to eat closer to the
ground.
Rotate young stock around the farm ahead of "adult
stock":
*Let the young stock into the fresh lengthy grassy paddocks first.
When they
move on to the next paddock put your older stock into that paddock.
Calves usually nibble, so with a length of grass they shouldn’t be near the
“larvae zone”. This way young stock gets the best feed, allowing them to grow
and gain weight, and there should be minimum contact with larvae.
Keep young stock on “safe paddocks”, after they’ve been drenched.
Rotate them in these safe paddocks. Older stock should have some immunity, but
they can still excrete eggs.
Rotate older stock in paddocks especially for them.
A check fecal egg counts is recommended for both groups.
Rotational Grazing:
Rotational grazing means your animals (herd/flock) move through each paddock on
your farm.
If you have 20 paddocks you could have a rotation of 20 days, or 40
days if they are to spend 2 days in each paddock.
Frequently, however the life
of the parasite is longer that the farm rotation.
BUT !! if you can divide your
farm into this many sections there is merit in managing your animals so they are
less likely to eat down towards
the base of pasture plants: less likely to eat
into the zone where most larvae are.
Safe pastures (or rather safer pastures!!):
Pastures that have been cut for hay or silage are considered to be safe from
parasites.
Crops and new grasses can also be considered worm-free.
Harrowing:
The idea of harrowing is that dung is broken up, and distributed on the paddock.
Animals enjoy resting areas “loafing areas”, or “campsites”.. These are often
under a tree or in some sheltered spot. These animals are not fussy where they
“relieve” themselves and they frequently do so in their resting site.
Now consider that there may be eggs in their dung. Harrowing through, and
distributing the dung means you could be distributing parasite eggs or larvae.
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Streams/creeks/ponds as a water supply:
It is most desirable to have “clean water” (in a trough) for your stock to drink.
 Using a stream, or pond, is an inexpensive way for your animals to get
drinking water.
Be aware that your animals are seldom fussy about where they
“relieve themselves”.
In and around drinking areas, animals expel their faeces (and their
“passengers”!!)
This results in the water, and the surrounding area, being laden with larvae.
Your very young animals:
Young milk fed young animals need access to pasture to aid rumen development.
During their time on the pasture, they can pick up parasite larvae from the eggs
their mothers, or other animals have previously excreted.
Ensure newly weaned animals have plenty of feed (nitrogen enhance the growth if
necessary) This can "dilute the " concentration of parasites on the pasture. It
certainly makes plenty of feed available for your young stock.
Drench newly weaned animals.
They need follow up drenches also.
After drenching transfer stock to “safe” pasture.
Goat and sheep:
Goats that browse, rather than being pasture fed, have a very much lower
parasite population.
After lambing and kidding the ewe and doe's immune system is less efficient.
This is a temporary.
If you de-worming these animals after they’ve had their young, it will help
minimize the exposure of parasites to the recently born, and the younger
animals.
Sheep and goats are mainly infested by the same species of worms.
Graze several animal species on your farm.
Most parasites are specific to the one species.
Graze weaner animals where other stock species have been.
Eg; Lambs, where cattle have been, and calves where sheep have been.
Stock numbers, and pasture growth:
With too many stock, or stock are on the same pasture for too long animals may
be forced to eat further down the grass plant, and more likely to ingest
parasites. Underfed animals just don’t have the immunity that well fed animals
have.
~~~~~~~~~~~~~~~~~~
Vaccinations.
How Vaccinations work:
The immune system identifies an attack by foreign substances.
eg: Bacteria & viruses.
When attacked by an antigen (Usually A toxin) antibodies are produced. The immune system responds, and identifies the invading antigen.
The immune system can distinguish between all different antigens.
Four components make up the immune system. They're collectively known as "white blood cells" or leucocytes. They 'fight' anything foreign that invades the body.
When an antigen (bacteria/virus) invades the body for the first time the immune system makes specific agents to deal with that invading organism.
The next time the immune system encounters an organism which it has previously met, it "remembers" what to do to, and the disease can be prevented. The "body" is said to have "acquired immunity".
A vaccine introduces the body to an altered and safe antigen of a disease.
The body responds by manufacturing a specific agent for that invading organism. The body then has gained immunity, without having suffering the disease.
Clostridial
diseases...
The Clostridial diseases: These can all be vaccinated against.
Blackleg:
(commonly called blood poisoning)
Malignant Oedema (commonly called blood poisoning)
Black Disease (commonly called blood poisoning)
Pulpy Kidney
Tetanus
These are all caused by clostridia. (Clostridium bacteria)
About
the Clostridial Bacteria.
The clostridial group of bacteria were created to survive!!
The 'insides' of the bacteria are surrounded by an extremely tough wall.
These clostridia can survive for years and years and years!!
They are known for their ability to form spores, and they'll do so in challenging conditions. These spores tolerate extreme conditions, especially heat.
They wont grow however until a suitable environment is found.
Clostridium are anaerobes, meaning basically that they can live without oxygen.
When these clostridium bacteria are active they'll produce the most powerful exotoxins known, and it's these exotoxins that are responsible for the colostridial diseases.
Many of these beasties may be found in soil. Some can live in the gut of a healthy animal, and are expelled in it's feces.
Unfortunately the diseases are frequently fatal.
Furthermore the first clue you may have that something is wrong is when you find an animal dead
The only way to prevent clostridial infections: is by vaccination.
Is it worth vaccinating for clostridial diseases?
Should you vaccinate???? Or not bother????
You will have the reassurance that your animals will be safe if you vaccinate.
Because of the bacteria's longevity: Do you know the previous use of your land stretching back many years?
Farmers may not be aware they have any clostridial bacteria on their farm until they find a dead animal.
After that farmers fastidiously vaccinate.
***
Farmers also need to protect themselves.
***
TETANUS:
Tetanus is a horrid disease which affects humans. It's often fatal.
The bacteria (Clostridial tetanii) causing tetanus (often called lockjaw) normally live in the soil.
Farmers:
There is merit in keeping your tetanus booster up to date.
a booster shot every ten years.
Leptospirosis:
(red water fever)
Leptospirosis in humans is a severe disease. And can be
easily 'picked up' from contact with an infected animals.
In humans the disease includes:
Fever (lasting for up to 10 days) plus muscle aches, head aches, stomach aches, vomiting, and an intolerance to light.
(Who is going to work with your stock while you are too ill to work?)
Don't presume that there is little likelihood of YOU being infected because: Many animals are mildly affected, or they may NOT have clinical signs.
Recovered animals become resistant to further infection by similar leptospiral
organism. However they can pass the organisms in their urine for some months.
Control: Ask your vet about having all your stock vaccinated.
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