Rift Valley Fever (RVF)

RVF is a mosquito-borne zoonotic viral disease affecting many animals, especially domestic livestock, and humans. It is most common in eastern and southern Africa. Sheep, in particular exotic, introduced breeds, are most susceptible.

It can cause fever, haemorrhage and abortion in pregnant animals. More than 90% of infected lambs die; mortality of adult sheep is as low as 10%. Humans can contract RVF from mosquitoes and possibly other bloodsucking insects.

RVF epidemics have a serious impact on the economy due to death of livestock, infection of humans and bans on livestock trade from RVF-infected areas.

Rift Valley Fever  - symptoms and prevention

Is an infectious zoonotic disease affecting sheep, goats, and cattle.

Rift Valley Fever (infectious enzootic hepatitis) and humans are susceptible to the  disease.

Rift valley disease is a viral disease of sub-Saharan Africa. The virus attacks the liver and causes symptoms ranging from fevers and listlessness to hemorrhage and abortion rates approaching 100% in pregnant sheep. It is transmitted by mosquitos. RVF is a notifiable disease and it is thus important for farmers to inform the State Vet and Animal Health Technician when they suspect the disease.

Vaccination of animals against RVF has been used to prevent disease in endemic areas and to control epizootics. Rift Valley fever is more deadly than West Nile virus. Animals should be moving away from standing water and moved to higher altitude areas. Caution must be exercised when handling infected tissues by wearing gloves, masks, goggles and by using viricidal disinfectant. The incubation period is 1 – 3 days.

Symptoms in animals:

Abortions, mortalities in young animals, jaundice, lagging behind, weakness and exhaustion, bloody diarrhea, bleeding from the nose and fever.

Symptoms in humans:

Influenza-like symptoms – headaches, muscle pain, joint pain, abdominal pain and nausea.

Prevention

Vaccinate sheep older than 6 months. Inactivated vaccine can be used in pregnant ewes. Animals must be given a booster within 3-4 weeks after initial vaccinations and then must be done annually.

Movement restrictions are recommended. No movement without notifying the Provincial State Vet.The disease is caused by the Rift Valley Fever (RVF) virus, a member of the genus Phlebovirus in the family Bunyaviridae and the disease is transmitted by mosquitoes.Limited to Africa in earlier years, it causes the enormous waste of livestock, especially in wet conditions

For decades Rift Valley fever has caused the illness and death of large numbers of livestock in Kenya and in much of sub-Saharan Africa. Increasing evidence linking the disease to human deaths as well has led epidemiologists to include Rift Valley fever on the list of emerging viruses (including HIV and Ebola) that infect thousands of people each year.

Clinical Signs

In young lambs the incubation period varies from 20 to 72 hours. Some lambs die suddenly without showing signs of this disease. Usually, however, affected lambs develop fever, refuse food, physically weaken, recline and die after a course of 24 hours. Mortality often reaches 95%.

In adult sheep the most common clinical finding is abortion. Most affected sheep show fever of 41 to 42 °C, abortion and vomiting. During fever, severe leukopenia, especially of neutrophils, forms.                

Controlling RVF in animals

•           Outbreaks of RVF in animals can be prevented by a sustained programme of animal vaccination. Both modified live attenuated virus and inactivated virus vaccines have been developed for veterinary use. Only one dose of the live vaccine is required to provide long-term immunity but the vaccine that is currently in use may result in spontaneous abortion if given to pregnant animals. The inactivated virus vaccine does not have this side effect, but multiple doses are required in order to provide protection which may prove problematic in endemic areas.

•           Animal immunization must be implemented prior to an outbreak if an epizootic is to be prevented. Once an outbreak has occurred animal vaccination should NOT be implemented because there is a high risk of intensifying the outbreak. During mass animal vaccination campaigns, animal health workers may, inadvertently, transmit the virus through the use of multi-dose vials and the re-use of needles and syringes. If some of the animals in the herd are already infected and viraemic (although not yet displaying obvious signs of illness), the virus will be transmitted among the herd, and the outbreak will be amplified.

•           Restricting or banning the movement of livestock may be effective in slowing the expansion of the virus from infected to uninfected areas.

•           As outbreaks of RVF in animals precede human cases, the establishment of an active animal health surveillance system to detect new cases is essential in providing early warning for veterinary and human public health authorities.

RVF FORESCASTING AND CLIMATIC MODELS

Forecasting can predict climatic conditions that are frequently associated with an increased risk of outbreaks, and may improve disease control. In Africa, Saudi Arabia and Yemen RVF outbreaks are closely associated with periods of above-average rainfall. The response of vegetation to increased levels of rainfall can be easily measured and monitored by Remote Sensing Satellite Imagery. In addition RVF outbreaks in East Africa are closely associated with the heavy rainfall that occurs during the warm phase of the El Niño/Southern Oscillation (ENSO) phenomenon.

Tips for dealing with Poisonous Plants

Inspect camps properly and on an ongoing basis for signs of poisonous plants. Know what poisonous plants are found in what camps, and when. Animals should be taken out of camps while getting rid of such plants. 

Good pasturing means that the veld is not over-utilised and good pasturing practises are applied.  Farmers should be especially careful during early spring when pasture is poor. Poisonous plants are usually the first plants to shoot, for example, gifblaar and gousiektebossies. Many poisonous plants are extremely toxic during this stage. Unfortunately, many animals prefer this attractive greenery to other not-so-attractive available food in the veld.

Gifblaar - Dichapetalum cymosum

When poisonous plants are interlaced with eatable plants, for example, Vermeerbossie and young Senecio plants, they are eaten by accident.

Animals suffering from certain mineral shortages (e.g. phosphor and calcium) can lose their natural ability to distinguish between eatable and non-eatable plants.

Overgrazing puts pressure on veld and poisonous plants take root easily. 

Sheep are primarily affected by

·         Geeldikkop

·         Poisoning by cardiac glycoside-containing plants

·         Vermeersiekte

·         Seneciosis

·         Gousiekte

·         Diplodiosis

Bitterbos takes over when veldt is over-utilized and is mainly due to ineffective veldt management. “Although it flourishes in different types of soil, it is seldom found in alkaline/brackish soil. It is found on plains and hillsides. It is an active intruder plant and associated with weakening poor veld. It is one the most important species taking over the Karoo. It usually blossoms during spring and autumn, but depending on weather conditions, can also be present during the year.

The bush often is eaten during times of pasture scarcity by adult small stock and cattle. Small amounts of bitterbos taken in with other pasture are not harmful though. Big amounts result in diarrhoea. Some animals die fast while others develop intense and even bloody diarrhoea. 

Reproductive efficiency

Sheep have the potential for multiple births.

Therefore, select #twins for replacements when possible.

With good management, mortality of twins should not be much higher than that of singles.

Measures of reproductive efficiency include age at puberty, fertility, #lambing rate, and #length of the breeding season. #Reproduction in sheep is strongly influenced by the environment. By most estimates, the heritability of reproductive rate is low, but breed differences exist. Fine-wool breeds are highly fertile and have been used successfully in crossbreeding programs to improve reproductive rate. Breeds that have been used under intensive management systems to increase lambing rate include the Finnish Landrace, Border Leicester, and Suffolk as well as Merinos, Dormers and Dohne Merinos.

Real hunters support responsible utilization of free ranging game

Recent events in the wildlife and hunting arena spurred worldwide condemnation of certain practices, latest of which was the shooting of a collared lion in Zimbabwe. 

It placed the spotlight on hunting and prompted responsible hunters that put conservation of nature and natural resources first and foremost, to call upon all hunters to refrain from participating in unacceptable hunting and associated practices.  

The South African Hunters and Game Conservation Association (SAHGCA) only supports hunting of wild animals in their natural state and in their natural habitat. SAHGCA members are diametrically opposed to the intensive and selective breeding of game animals of all species solely for hunting purposes, as it is incompatible with the definition of hunting.

Efforts to justify the intensive breeding of any species for hunting purposes are none other than defending unacceptable practices. Such practices have already tainted the country’s image as a hunting destination. South Africa’s neighboring countries capitalize on our poor image and lure overseas hunters with a promise of free roaming game to be hunted in real safari fashion. This has a negative impact on local game ranchers that still offer safari style hunting according to responsible hunting principles.

Although eco-tourism and hunting on extensive areas (that far exceed the area under formal protection) in Africa play a major role in conservation and rural economies, it is time for hunters to do introspection. Not only is the reputation of hunting at risk, but also the reputation of the country that is supposed to be a leader in the field of conservation. Irresponsible hunting practices, luring of game animals from reserves into hunting areas, put and take practices and intensive breeding of game animals for hunting do not bode well for the future of hunting.

Members of the SAHGCA have grave concerns about the negative biodiversity impacts of these practices and call on government to fulfill their constitutional obligations as Trustee of our wildlife heritage. It must ensure that while promoting justifiable socio-economic development, the environment is protected for the benefit of present and future generations, through reasonable legislative and other measures that prevent ecological degradation, promote conservation and secure ecologically sustainable development and use of natural resources. In this, incentives should be developed for extensive game farmers that not only contribute to the economy, but that also make a huge contribution to South Africa reaching its conservation targets.

SAHGCA also calls on hunters, professional hunters and outfitters to uphold the principles of responsible hunting. It is impossible to defend hunting in the wake of recent events in the hunting arena that shook the world. We make no distinction between ungulates and predators in this regard. Should we hope to sustain hunting for the foreseeable future; hunters need to refocus their practices on responsible hunting of wild animals in their natural state. The fact that we still have many game ranches and reserves with free roaming game animals is part of South Africa’s competitive advantage as a tourism and hunting destination. However, irresponsible practices negate the positive aspects of our extensive game areas.

Responsible hunters want free roaming game animals. Such animals offer hunting in its best form as well as a healthy protein source that is free from remedies that are a necessity in livestock production. Game meat produced in agricultural type production systems where remedies are required to address increased parasite loads associated with small enclosures, detracts from the benefits consumers have already associated with free ranging, healthy game meat. SAHGCA believes there is a huge potential to grow the game meat market, but it should be labeled and certified as free ranging.  

For more information please contact SAHGCA President Dr Gerhard Verdoorn on 082 446 8946. 

Illegal poisoning of wildlife on the increase

The recent death of vultures, Blue Cranes, Brown Hyenas and other wildlife due to illegal poisoning should be a wake-up call for South African conservation authorities, law enforcement agencies and conservationists. While rhinos faced a grave poaching threat, other equally important wildlife species, especially scavengers and predators are at risk of joining rhinos on the route of steep decline if the current spate of illegal poisoning continues.

The death of sixty-six vultures in the Lowveld was confirmed by toxicological analysis as a poisoning case; at least one carbamate pesticide was detected in the analysis. More recent incidents in which ungulates were snared and their carcasses poisoned to kill vultures for traditional medicine are just the tip of the iceberg. In 2012 mass poisoning of Blue Cranes occurred in the Karoo. This is yet, unresolved.

 Recently farmers reported that at least sixteen Brown Hyenas died probably as a result of poisoning in the Limpopo Province, and earlier this year Black-Backed Jackals were deliberately poisoned in the Addo Elephant National Park. Poisoned baits aimed at rhinos are often found in the Kruger National Park and Associated Private Nature Reserves. Fortunately, no rhinos have been poisoned to date in this important conservation area. Unfortunately many of the wildlife poisoning incidents become “cold cases” as the culprits are never found.

Deliberate poisoning of wildlife is definitely on the increase. Some of the poisonings are committed by poachers who kill wildlife for traditional medicine; vultures are mostly targeted for their heads that are used in divination. Lions have also allegedly been poisoned for their bones as part of the lion bone trade that services the Far East. Elephants have been poisoned in Zimbabwe to obtain their ivory, probably also for the lucrative illegal ivory trade in the Far East.

What is of grave concern is the illegal use of pesticides and other poisons such as sodiummonofluoroacetate by livestock and wildlife owners to kill predators. Despite a concerted effort by the livestock industry driven Predation Management Forum (PMF) to offer farmers alternatives to poisoning predators, some individuals do not heed to warnings to refrain from illegal use of pesticides and poisons. Provincial conservation agencies have warned that the liberal distribution and use of sodiummonofluoroacetate (also known as Compound 1080) is illegal, and should any retailer or landowner be found in possession of it, they will be prosecuted. There is reason to believe that vultures in the Eastern Cape and the sixteen Brown Hyenas in Limpopo were poisoned with Compound 1080; further investigations are geared to identify the particular toxins that were used to kill these animals.

State departments are at a loss for funds to conduct toxicological analysis and often request the Griffon Poison Information Centre to fund such analyses. Villa Crop Protection, one of the largest agricultural remedy suppliers in the country supports the center with financial backing to conduct toxicological analysis. Villa MD, Dr André Schreuder says, “Illegal poisoning of wildlife is a huge risk not only to South Africa’s natural environment, but also to agriculture. 

Many of our important products are deliberately misused to poison animals. It creates a negative perception of agricultural remedies if criminals misuse them to poison wildlife. Villa is determined to undermine individuals who poison wildlife illegally by supporting investigations into their crimes”. Tommy Fraser, a director of Villa Crop Protection, game farmer and conservationist believes that a concerted effort is required from conservationists, farmers and law enforcement agencies to stem the poisoning of wildlife: “poisoning is like a death warrant to all life forms. It hits far beyond the scope of the intended target. If nothing is done, we may not see our rare birds like vultures fly into the 22^nd Century”.

Livestock owners that experience stock losses due to predation are likely to consider poison as a remedy. Only the poison collar is legal and only after a permit is obtained from the conservation authorities. It is well known that aldicarb, carbofuran, methomyl and Compound 1080 are illegally used to poison predators. The results are devastating and over the past two years many vultures have perished at the hands of those who lay out poisoned baits.

The Griffon Poison Information Centre endeavors to rid the country of illegal poisoning. Its supporters, many of which are farmers, are gathering intelligence on those individuals who illegally poison wildlife. On the other hand it is offering a hand of assistance via the Predation Management Forum to mitigate predation. Information and assistance from www.pmfsa.co.za.

Any information about illegal wildlife poisoning maybe called into 082-446-8946 or nesher@tiscali.co.za.

For more information, call Dr Gerhard Verdoorn on 082-446-8946

Keep your clip clean

Wool can and should be marketed as a natural, environmentally-friendly quality fiber. Anything that undermines this image can lead to consumer resistance and have a negative effect on the marketability and price of wool.

Contamination of wool by foreign objects – like black hair, bale twine, wire, bolts, cigarette butts, matches, dog hair, pieces of cloth – pose a serious threat to the long-term sustainability and profitability of wooled sheep farming.

Contamination of wool can result in big claims against buyers or processors, and damages the reputation of the clip.

Hard objects in a bale can damage core sampling and wool processing machines, while deviating fibers (black hair, Kemp) can spoil meters of fabric as these only show up at the final stage of processing.

In addition, increasing worldwide antipathy towards any form of pollution, and stricter regulations, particularly by the European Union, about environmental pollution, are putting pressure on the wool industry to eliminate chemical contaminants and ensure that pesticide-free wool products reach the market.

The main sources of contamination are:

·           Foreign objects originating in the shearing shed, e.g. fertilizer bags, baling twine, pieces of metal, clothing, cigarette butts, etc.

·                     Wool packs containing loose material, usually fibers.

·                     Sheep branding inks and certain wound dressing containing discoloring compounds.

·                     Colored fiber resulting from crossbreeding or non-woolled sheep breeds running with Merino sheep.

·                     Residues from pesticides used for the treatment of external parasites on sheep

What producers should do to prevent contamination

 

In the shearing shed:

It is vitally important for all producers to maintain good management principles in the shearing shed to avoid contamination prior to classing and packing. No matter how well-classed the clip, if it is contaminated with baling twine or other foreign objects, the buyer will penalize it.

·                     Clean the shed thoroughly before shearing commences and store away any tools, bolts and other metal objects.

·                     In order to minimize possible contamination with animal hair, feathers, baling twine, etc., ensure that the holding pens are clean.

·                     Educate shearing team and workers about the dangers of contamination.

·                     Provide a rubbish bin with a lid for cigarette buts and other rubbish.

·                     Ensure that proper supervision is exercised during shearing.

·                     No dogs or other animals should be allowed in the shed.

·                     Use a rubber rake rather than an ordinary broom with hair in the shearing shed.

·                     Never use jute bags in the shearing shed, be it for wiping feet or sharpening the shears on.  Rather use carton, paper or a piece of sheepskin.

·                     Never use baling twine in the shearing shed, even for hanging tools or other gadgets against the wall.

·                     Make sure that shearers don’t use twine for their shears.

·                     Shearers should preferably not be allowed to sleep in the shearing shed.

·                     Always shear purebred woolled sheep first.

During shearing and classing: 

·                     Wool stained with branding ink, tar, urine, dung, blood, paints or discolored by fungi or chemicals must be removed before shearing, packed separately and marked as “Brands”

·                     Remove all bloodstained wool during the shearing process.

·                     Request the shearers to remove pieces of skin cut off during shearing. Skin pieces quickly become dry and hard and can damage carding machines.

·                     Topknots and cheek wool can contain hairy fibers and must, therefore, be packed with the lox, irrespective of how long and attractive they look.

·                     Colored fibers are often found around the horns and should not be packed with bellies or pieces to prevent contamination. 

First 2015 Blog post- farming perspective

I didn't update for a couple of months, due to academic editing, proofreading and thesis formatting assignments.

However, I'm back on the blogging track at the crack of dawn and back into the flow of everyday farming life. Even though we are flooded with information, here we can go as slow as molasses if necessary. 

Betting your farm that these tips and info are down to earth, covering a lot of ground. This is the place to get the cream of the crop solutions for real problems. So follow your gut reaction and explore this site. Don't let any grass grow under your feet and remember for everything there is a season. 

A farmer's productive capacity is directly related to the health of his/her soil.

Tips to ponder: If it ain't broke, don't fix it. 

Just staying one day ahead of yesterday.

 Let sleeping dogs lie. 

Always drink upstream from the herd. 

Nature's first green is gold! 

The more we pour the pesticides, herbicides, and chemicals into farming, the more we knock out the mechanism that made it all work in the first place. 

May you enjoy productive farming experiences!