Have you decided how you will deal with Facial Eczema if spore counts start to rise in your area? Even if you have never had Facial Eczema in your area before, it wouldn’t hurt to have a plan of action ready, such as zinc oxide or zinc sulfate in the medical cupboard. Ask your vet if spore counts are monitored in your area, maybe offer your farm as a monitoring area and inquire whether you could be contacted if there are any Facial Eczema concerns in your region. Maybe you could consider setting up area networks where everyone can be contacted when spores are on the rise. Check into where spore counts can be done and educate yourself on how to prepare the samples for the Lab.

Facial Eczema by Dr Neil Towers, Ruakura

Fungus grows on dead material. Ideal conditions for fungus to grow include drought, dieback of grass, followed by rain. Watch out when you get warm overnight temperatures, high humidity and light rains or heavy dews, i.e. pasture base continually damp.

Influences on fungal growth include:

• latitude
• altitude – higher altitudes safer
• aspect – if pastures facing sun they will dry out quicker, so cold, windy, dry slopes are safest.

Facial eczema is not eczema as such, but the result of secondary liver damage. Tissue damage will occur in any area where skin is exposed to sun. Facial eczema is very stressful for the animal (although if the bile ducts are not completely blocked off, liver should recover).

Symptoms of Facial Eczema to look out for include:

• Animal seeks shade
• Ears droop
• Swelling, warmth around affected areas, such as eyes, ears or face
• Signs of jaundice in gums, eyelids
• Animal will scratch, bite or be edgy
• Animal may rub eyes against fence posts
• Tip of tongue may be ulcerated
• Frequent urge to urinate. May squat.

Control Strategy:

Identify and avoid dangerous pastures

1. Use fungicide
2. Recognise dangerous weather conditions
3. Count spores
4. Substitute non-toxic feeds such as hay or silage
5. Listen to radio spore counts but treat with caution – general information and conditions will vary in different areas.

Fungicide:

1. Use a benzionidazole such as Benlate
2. Will not kill fungus already present, but will stop it from growing further.
3. Reduces spore rises by 55 – 65%
4. Provides safe pastures for 4 – 6 weeks
5. Respray if 7.5mm of rain (or more) falls within a day or so
6. Must do a good job. Spray the entire area to be grazed

Zinc Dosing:

• Must be done before animals eat toxins
• Care needed with dose rates
• Regular dosing gives better protection

Oral dose – zinc oxide

• Adding to water – zinc sulphate
• Slow release bolus – zinc oxide
• (still experimental, may not be suitable for alpacas)

Possible Developments:

• Possibility of bio-control
• Almost all NZ spores are toxigenic
• Most overseas spores are non-toxigenic. If these could be grown in New Zealand they should reduce toxic levels by 80%, but it would be necessary to isolate and get enough of these non-toxic spores to cover a large area. In addition, they don’t survive beyond one season.

Spore Counting

When cutting material for spore counting, take whatever part of the plant that animals eat. Spore counting is useful when spores are rising; not so good when spores are dying.

Other fungi can produce different toxins that could cause liver damage. Benlate won’t help these toxins.

Facial Eczema Action Plan

Recognise the Toxic Conditions:

1. Warm humid weather between January & May
2. Wet pastures during most of the day and high overnight temperatures above 12oC

Remember: the toxicity of a pasture depends on several factors:

1. The spore count
2. The age of the spores. Young spores are more toxic.
3. The grazing level. Animals grazing to the base of pastures are most at risk.
4. Prior exposure of the animals to toxic spores.
5. The length of time toxic spore levels are consumed.

Prolonged exposure to low toxin doses can be as dangerous as a single high dose of toxin.

STRATEGIES FOR AT RISK DISTRICTS

1. Monitor the spore counts on your farm. Spore counts can range from 0 – 300 000 on the same farm
2. Identify the paddocks or areas on your farm that are dangerous. Avoid these areas or breakfeed using a crop as a large proportion of the diet.
3. Plan a long-term zinc oxide dosing system. This is 90% effective, compared to 60% for crisis dosing. (Refer to FarmFact 1-8 for drench recepies)
4. Dose cows daily and calves twice a week.
5. Purchase enough zinc oxide for 5 months. Supplies often run out during a crisis.
6. Start drenching in early January when you notice counts beginning to rise or sooner if the situation warrants.
7. Assume that dangerous conditions will occur
8. Ensure dose rates are up to maximum recommended levels if spore counts are above dangerous levels (60 000s/g)
9. Check mixing calculations carefully (refer to FarmFacts 1 – 8 Facial Eczema – Zinc Treatment, Recipes and Dose rates)
10. Get someone else to double-check your calculations

Finish zinc dosing only when all danger is past. In Northland, Waikato and Bay of Plenty this can be well into May in some seasons. (After spore counts have dropped there is still a danger of eczema due to the Serum GGT levels in cattle).

Consider spraying an area of the farm with fungicides as well as drenching with zinc oxide. Spray in early January to slow the build up of spores. Fungicides reduce the number of spores produced by 55-65%. This area provides a safer area for stock in high danger periods.

Use supplementary feeding to reduce the intake of spores in danger times especially from low level grazing.

A Facial Eczema “contingency stack” of silage is a flexible option as you can match feeding it to the danger periods. A crop may only cover part of the risk period.

Supplements may also allow you to feed stock longer on a ‘safer area’ of the farm.

Water Trough treatment is not reliable enough for high risk dairy farms.

Remember that young stock are at high risk.

Check young stock that may be out grazing to make sure protection measures are in place. Many traditionally ‘safe’ areas for FE have experienced bad outbreaks of facial eczema in previous seasons due to poor control measures.

Get all culls off the farm early. This reduces grazing pressure.

Do not top pastures after ryegrass seed-head appears. Topping late leaves litter on which the spores multiply rapidly. Topping during danger periods is very unwise as spores like new litter to grow on.

A Short Primer by Stephen Mulholland

In most discussions of animal immunity and vaccinations, you will come across references to “Ig”. This is an abbreviation for “immunoglobulin.” An immunoglobulin, or Ig, is a protein molecule that is produced by the immune system to help recognize invading organisms (bacterial, viral, fungal, and parasitic worms) and mark them for elimination by other cells of the immune system. Ig’s are more commonly known as “antibodies.” Measuring the Ig level, or quantity of antibodies, in the blood therefore provides a good indication of the health and capabilities of the immune system.

When a baby mammal is born, it has no antibodies at all, and is therefore very vulnerable to infection. The mother’s colostrum contains a large number of antibodies produced by the mother to be passed on to the young. These antibodies provide protection in the weeks and months after birth while the baby’s own immune system is developing. The stronger the mother’s immune system, the better the protection that the baby receives via the colostrum: this is why it is recommended to give the mother a vaccine booster shot a few weeks before birth, as it boosts her antibody levels against common paddock diseases, and this improved protection is passed on to the cria. If the baby does not get any colostrum, it is very vulnerable to infection and is much more likely to die. A plasma infusion can save such an at-risk cria by providing it with the antibodies of an adult animal.

Vaccination presents the immune system with a sample of what some of the common and deadly infectious organisms look like. Vaccinating an animal in the first few days after its birth is pointless as there are not enough immune cells in the blood stream to effectively respond – it has its mother’s antibodies, but no means yet of producing its own. To give a cria’s own immune system enough time to develop, its first vaccination should be given six weeks after birth, with a second dose four to six weeks later. The repetition induces the immune system to create “memory cells,” which are antibody (Ig) producing cells that circulate in the blood and watch for more invaders. The memory cells can last for months or years. By giving periodic booster vaccinations, we refresh the population of memory cells, keeping the immune system primed to fight off those invaders.

The primary components of the immune system are the leukocytes, or “white blood cells”, manufactured in the bone marrow and released into the blood stream. Leukocytes come in many different varieties, but they are all designed to work together to identify foreign invaders and destroy them. The combined mass of cells of the immune system is about the same as the liver, making the leukocytes, as a group, one of the largest “organs” in the body.

A subtype of the leukocyte is the lymphocyte. Broadly speaking, there are two different classes of lymphocytes, the T-lymphocytes (T-cells) and B-lymphocytes (B-cells). The T-cells are involved in what are known as “cell mediated responses”: these respond to cells which have foreign bodies displayed on their surface and can eliminate virus-infected and cancerous cells. T-cells can also respond to chemical signals to activate and search for invading bacteria. The B-cells are involved in the production, presentation, and retention of antibodies.

Immunoglobulins are the primary tools of the B-cells. Specialized B-cells wander the body looking for cells or particles that are foreign. Finding an invader is only the first step. The rest of the immune system must be notified and mobilized. Almost any large molecule (protein, carbohydrate, fat) can induce an immune response. These molecules are known as antigens, which stands for “antibody generators”, and a single bacterium or virus may be covered by thousands of them. The antigens are chopped up into small pieces, and those pieces are then presented to the antibody-producing cells.

Every day the body produces millions of different antibody-producing cells in the bone marrow. Each of these cells produces a different, unique antibody. The end-tips of the antibodies have what is known as a “variable region” that is different for every antibody and forms a unique three-dimensional shape. If that antibody finds an antigen that has the mirror inverse of the shape at the variable-tip, then the antibody and antigen will bind to on another like a key fitting into a lock. When that happens the B-cell that makes that particular antibody knows it has a “winner” and starts to mass-produce that antibody. An invader coated in antibodies can be easily identified and eliminated. The antibodies coating the surface of invading bacteria or virus often have an additional effect of preventing them from attacking the body or reproducing, speeding their elimination. A single infectious organism can trigger the production of dozens or even hundreds of different antibodies against it, as there will be lots of different “fits” — since each organism has many different antigens on its surface. These first antibodies vary in their efficiency for targeting the foreign invader, but as time goes on the response will “mature” as the immune system adapts and produces antibodies better able to target the invading antigens.

Vaccines are mixtures of antigens that can activate the immune system without causing an infection. One common tool for making a vaccine is to use heat-killed bacteria or viruses. The immune system is thus presented with the shell of the invader, and can start producing antibodies against those antigens.

Because we are exposed to millions of different antigens, the immune system has a method to distinguish occasional threats from persistent threats. If it wasted all its efforts mass-producing antibodies against infections you will never experience again, it could not be ready for the more dangerous diseases. For this reason there are memory cells. When an infection runs for a long time, or if a creature gets infected by the same disease again and again, some of the best antibody-producing cells will convert into memory cells. These are antibody-producing cells that are effectively in storage. They drift through the bloodstream, often for years, waiting and watching for the invader for which they optimized to reappear. If that invader comes back, the memory cell immediately kicks into gear: it makes thousands of copies of itself, starts cranking out antibodies, and mobilizes the rest of the immune system against the attacker. This speeds the response time of the immune system from weeks to days, or even hours.

Vaccinations are typically given in two doses four to six weeks apart because this is the best method to activate the immune system (first dose), and then cause a maturation of the response and the production of memory cells (second dose). Booster shots cause the memory cells to activate and reproduce, increasing their numbers in the bloodstream. This is necessary because the memory cells do eventually die, so without periodic boosters the immunity would gradually fade. For most human vaccines we know how long the memory cells against various antigens last, and thus doctors prescribe different periods for booster shots (3 years, 10 years, etc.). In camelids, the lifespan of the memory cells is not known, but as the common vaccines are known to only provide about 12 months of protection in cattle and sheep it is recommended that booster shots be given at least once and preferably twice per year to ensure protection.

If you ever give a new type of vaccine (such as switching from 5 in 1 to 10 in 1) you need to give the two doses, about six weeks apart, to trigger the production of the memory cells.

Recommendations for vaccinations:

1. Many different vaccines are available.
2. Ask your vet about what is best for you.

Newborn cria

• 1 ml of vaccine at 6 weeks, subcutaneous injection
• 1 ml of vaccine at 10-12 weeks, subcutaneous injection

Adults

• 2 ml of vaccine every 6-12 months, subcutaneous injection

Adult animals should be given a booster shot every 6 to 12 months. Once a year may be enough, twice a year provides additional security. Most animals in NZ need some selenium supplementation, and the vaccine is a good time to do so. Selenated vaccines should not be given to newborn animals, as it can result in a selenium overdose. If you are unsure of the selenium levels in local feed, consult your vet.

Adult animals can be switched from one vaccine to another (for example from 5 in 1 to 10 in 1). If switching over, remember to give 2 injections about 6 weeks apart to induce the formation of memory cells, after which 1-2 boosters per year should be given.

Feeding Ruminant Protein to Ruminants is Banned

Biosecurity invited the NZ Llama Assn. to be part of its Ruminant Protein awareness programme. They asked to include our logo on the information that they produce, and also that we make our members aware of the programme and requirements of the Regulations.

The Biosecurity (Ruminant Protein) Regulations, 1999 aim to preserve New Zealand’s BSE-free status and manage the risk of a BSE outbreak.  The regulations prohibit the feeding of ruminant protein (except dairy produce) in any form to ruminant animals.  The purpose of this feed ban is to minimize the risk of contamination by ruminant protein, of feed intended for ruminants in feed mills that also produce feed for non-ruminant animals.

Bovine Spongiform Encephalopathy (BSE) is a disease of cattle. The disease spreads when cud-chewing animals like cattle, sheep, goat, deer, llamas and alpacas consume feed derived from BSE-infected cattle. It takes less than one gram (the size of a peppercorn) of brain tissue from a BSE-infected animal to cause an infection. Therefore you must not feed cud-chewing animals anything that contains ruminant protein such as meat-and-bone-meal (MBM), blood meal, blood-and-bone meal and bone meal. Dairy produce is excluded from the definition of ruminant protein.

To ensure BSE doesn’t infect New Zealand ruminants, feed and fertiliser must be labelled correctly and conform to the requirements set out in the Biosecurity (Ruminant Protein) Regulations 1999.

The labelling requirements apply to anyone who produces, sells, or distributes feed or ruminant protein containing fertiliser.

The Regulations define feed as any food for animals produced in premises where ruminant protein is produced, rendered, or utilised.

Obligation to label Feed

All feed that contains ruminant protein must display the following label on the front of the feed bag.

Notice: Not to be fed to sheep, cattle, deer, alpacas, goats, or other ruminant animals

Feed that does not contain ruminant protein must display one of the following notices on the feed bag.

Notice: Suitable for feeding to (insert ruminant species or type)

Notice: Suitable for inclusion in feed intended for ruminant animals

There can be no variation to the words or phrases on the label.

For more information about BSE, go to http://www.biosecurity.govt.nz/tse

Camelids are susceptible to this disease. Although cases are relatively rare and transmission from one animal to another has not been documented, nevertheless Tb is a serious issue that you should educate yourself on. The disease is regarded as a threat  primarily because it is possible for humans to become infected with bovine Tb. The Animal Health Board scheme is voluntary for camelids but all owners are encouraged to take part.

The AHB’s campaign to eradicate bovine Tb from New Zealand works on two fronts – disease control and vector control.

Disease control aims to control and contain the spread of the disease within farmed animals, while vector control aims to control and contain the wild animal species mostly responsible for spreading the disease. The possum is recognised as the main cause of Tb infection in cattle and deer herds. Observations show, that when infected, sick possums appear during daytime, they attract the attention of inquisitive animals. This allows Tb to pass through respiratory infection. The control of possums is doubly important. Not only will reduced possum numbers reduce the likelihood of interaction between farm stock and infected possums, but it will also mean the collapse of the disease in the wild in those areas where possum numbers are kept at very low levels.

What should you do?

1. Establish what type of Movement Control area you are in and the rules related to your area.
2. To join the voluntary scheme phone Agriquality 0508 00 11 22
3. Control possums and other pests on your property.
4. If you plan to show, plan to Tb test.
5. Request llamas entering your herd be tested before they arrive
   or isolate until tested.

For more information on Tb 0800 4 TB INFO (0800 4 824 636)

To educate yourself about Tb, visit the Animal Health Board website and view pages on

• National Pest Management Strategy
• Animal Status Declaration Forms
• Herd Status
• Infected Herd Information
• Movement control
• Tb testing
• Farmer’s Responsibility Code
• Understanding Tb control
• Tb Control Basics
• Declared Movement Area Map
• Vector Control Programmes