Up to 80% of Flocks Could Be Scrapie-Free in Next Five Years

icelandic sheep réttir

The ARR gene, associated with scrapie resistance, was recently discovered in sheep in West Iceland, igniting optimism for breeding scrapie-resistant herds. Experts estimate that with strategic breeding, up to 80% of sheep herds could possess the protective gene within four to five years.

A landmark discovery

In early 2022, researchers discovered several sheep from an East Iceland farm that carried the scrapie-resistant gene ARR. This was the first time the genotype had been found in Iceland, and genetic researchers recognised that the discovery could prove pivotal to winning the fight against the disease, which has plagued Icelandic farms for over a century.

As noted in an article in IR magazine, scrapie is not transmitted through bacteria or viruses but is believed to originate from a prion protein, which leads to a deadly, progressive disease that deteriorates the nervous system of the affected animals. Unlike bacteria and viruses, prions present a unique challenge, being almost indestructible. Before the discovery of the ARR gene, when the disease was diagnosed in a sheep, veterinarians would need to cull the entire herd – and sometimes even sheep from surrounding farms, as well.

As reported by RÚV yesterday, the ARR gene has now also been unexpectedly discovered in sheep in West Iceland, more specifically in Vífilsdalur in Dalasýsla. Further investigations of related livestock in the region revealed its presence on three additional farms: Háafell, Geirshlíð, and Sauðafell.

80% resistance over next four or five years

Speaking to RÚV, Eyþór Einarsson, a sheep farming consultant at the Icelandic Agricultural Advisory Centre, suggested that the unexpected discovery of the gene gave reason for increased optimism in breeding scrapie-resistant sheep.

Eyþór noted that several farmers are now in the position to exclusively breed lambs that possess the protective, or potentially protective gene, ensuring that all lambs surviving the winter would carry the gene. He estimated, therefore, that these farmers could breed up to 80% of their herds with the protective gene within the next four to five years.

Eyþór added that with the gene being identified in this unrelated livestock — that is, in West Iceland — the process could be significantly accelerated. The unexpected discovery of the gene in the region raises hopes that it could be found more widely across the country; he encourages farmers to continue diligently sampling.

Eyþór also mentioned that a certain diversity was beginning to emerge in the stock carrying the gene. In addition to the two coloured rams previously identified, several yellowish ewes, both horned and polled, have now been added. This discovery should make it relatively easy to breed a colourful and diverse stock within a few years.

Deep North Episode 25: Good Breeding

iceland sheep breeding

This April, sheep at Bergsstaðir farm in Northwest Iceland were diagnosed with the fatal degenerative disease known as scrapie. In accordance with regulations, the 700-some sheep were culled to prevent the spread of the disease to neighbouring farms. We revisit our 2022 article, Good Breeding, to see what’s being done to fight this deadly disease.

Read the full story.

deCODE genetics to Join Efforts to Eradicate Scrapie

Ólafur Magnússon og frú bændur á Sveinsstöðum Trú frá S

The biopharmaceutical company that helped Iceland process COVID tests throughout the pandemic is now set to join another important project: the battle to eradicate the fatal disease scrapie from the Icelandic sheep population. RÚV reports that this spring, deCODE genetics will begin analysing genetic material from sheep to determine whether they carry a genotype that protects against the degenerative disease. Scrapie was recently diagnosed at a farm in Northwest Iceland, in a region where it had never been detected before.

Scrapie is often described as the ovine equivalent of mad cow disease. If a sheep tests positive for scrapie, the entire herd is culled, the entire farm’s hay must be destroyed, and the farm and its implements must be sanitised, either chemically or through fire. Even despite these measures, the disease can remain dormant in the environment for decades. The disease takes both a financial and emotional toll on farmers.

Researchers have recently discovered two genotypes in the Icelandic breed of sheep that appear to protect the animals from scrapie: ARR and T137. Breeding programs with those sheep have begun in efforts to eradicate the disease from Iceland.

Read More: Good Breeding

Until now, Icelandic researchers have had to send genetic samples to Germany for analysis in order to determine whether sheep carry the protective genotypes. With the help of deCODE genetics, it would be possible to test the samples locally. Researchers hope to test the existing stock more broadly as well as, of course, the offspring of the sheep that have already been found to carry the genotypes to see whether they have been passed down.

“If this collaboration with deCODE genetics works out, then hopefully it will be possible to test these samples in Iceland,” stated Eyþór Einarsson of the Icelandic Agricultural Advisory Centre. “And they also have a large capacity, and can handle the project, because the number of samples that will need to be analysed will multiply in the coming years as we get more rams in circulation that carry these genotypes.” Eyþór stated that there could be as many as 40,000 samples that need analysis by next year, and further research into the existing stock would also be necessary.

“This is really exciting and gives us hope and optimism for the future that there is a sort of definite response to this scrapie issue.”

Scrapie Diagnosed in Northwest Iceland

Sheep in Iceland

The degenerative and fatal disease scrapie has been diagnosed in sheep at Bergsstaðir farm in Northwest Iceland, in the Húnavatnssýsla district, RÚV reports. In conformance with Icelandic health regulations, 690 sheep will be slaughtered as quickly as possible to prevent the spread of the disease to other herds. It is the first time the disease has been detected in the region, which will have an impact not just on Bergsstaðir but the entire district. Scrapie is not transmissible to humans.

Scrapie is often described as the ovine equivalent of mad cow disease. If a sheep tests positive for scrapie, the entire herd is culled, the entire farm’s hay must be destroyed, and the entire farm and its implements must be sanitised, either chemically or through fire, as the disease can remain dormant in the environment for decades. As a result, even after this deep-cleaning, farmers are not able to raise sheep on the land for a set time, and the scorched-earth policy may even affect neighbouring herds and farms.

The Miðfjarðarsveit area, where Bergsstaðir farm is located, will now face significant restrictions on sheep farming for the next two decades, including a ban on transporting sheep between locations and transport of other materials.

Researchers have recently discovered two genotypes in the Icelandic breed of sheep that appear to protect sheep from scrapie: ARR and T137. Breeding programs have begun in efforts to eradicate the disease from Iceland.

Read more about the goal of eradicating scrapie from Iceland in the article Good Breeding.

Scrapie-Resistant Sheep to Enter Market this Fall

sheep breeding iceland

Up to 15 rams with scrapie-resistant genes will be sold for breeding this fall. Bred in Reyðarfjörður in East Iceland, the sheep carry a special gene and it is hoped that they will help form a more resilient stock in Iceland.

The gene, called ARR, is not found anywhere else in Iceland. It has been recognised internationally as scrapie-resistant, and herds with the ARR gene have already been bred in Europe for some two decades.

Scrapie is a fatal, degenerative disease found in sheep and goats, the ovine equivalent of mad cow disease. There is no cure, and even one case of scrapie can be a death sentence for an entire agricultural community. If a sheep tests positive for scrapie, the entire herd is culled, the entire farm’s hay must be destroyed, and the entire farm and its implements must be sanitised, either chemically or through fire. Even after this deep-cleaning, farmers are not able to raise sheep for a set time, and the scorched-earth policy may even affect neighboring herds and farms.

After the ARR gene was found out East, an effort was made to breed the gene into the stock as much as possible. There are now some 50 total rams that carry the gene.

Steinn Björnsson, a farmer in Reyðarfjörður, has said that the rams are expected to go for a modest amount. In an interview with RÚV, he stated “after all, sheep farmers have so little money that they would never be able to buy this if they were any more expensive.”

In a recent statement on their website, the Icelandic Food and Veterinary Authority has designated priority zones for the resistant stock. With only a small supply of the so-called “golden rams,” the stock is to be used as effectively as possible, with farming communities recently affected by scrapie and with herds of 300 or more given first priority.

For the full story on the fight against scrapie and the efforts to breed this new, resistant stock, read more in our article: Good Breeding. 

Scrapie-Resistant Sheep Multiply in East Iceland

Karólína Elísabetardóttir - Hvammshlíð - Húnavatnssýsla

The lambing season is going well at Þernunes farm in Reyðarfjörður, East Iceland, where 27 lambs have been born that carry the ARR genotype that protects them against the fatal disease scrapie, RÚV reports. The genotype was first found in Iceland on this very farm last January, through a research project that analysed thousands of genetic samples from sheep across the country. Researchers believe that careful breeding of sheep that carry the ARR genotype could eradicate scrapie from Iceland.

Read More: Good Breeding

Scrapie is a degenerative and fatal disease that affects sheep. Because it is highly contagious and can persist in flocks for decades, a flock in which the disease is discovered must be culled. Within the European Union, sheep that carry the ARR genotype do not need to be culled, even when scrapie is diagnosed within their flock, as research shows the gene protects them from both contracting and transmitting the disease.

Þernunes is home to the only ram so far found in Iceland to carry the gene: Gimsteinn (Gemstone). He carries the genotype on one chromosome, meaning that his descendants have a 50% chance of inheriting it. Þernunes farmer Steinn Björnsson says that by the end of lambing season, he expects around 40 of the farm’s lambs will carry the gene.

Another genotype known to protect sheep from scrapie, T137, was also recently found in at least four Icelandic sheep. Extensive research in Italy has found that T137 protects sheep from scrapie, but it is not officially recognised by the EU as the ARR genotype.

Good Breeding

Ólafur Magnússon og frú bændur á Sveinsstöðum Trú frá S

A sheep farmer’s worst nightmare is if one of his sheep starts to scratch more than usual. If their sheep start to show nerves, tremble, or grind their teeth, they should be really worried. An unstable walk or sheep that spend most of the time lying down might be showing symptoms of scrapie, the ovine version of mad cow disease. 

Scrapie isn’t spread by bacteria or a virus – it’s thought to be caused by a prion protein. The result is a fatal, degenerative disease that affects the infected animals’ nervous system. While bacteria and viruses are hard to deal with, prion proteins are in a league of their own, nearly impossible to get rid of. They can withstand an eight-hour boil and only the strongest chemicals will clear them. For sheep, an infection is a death sentence, effectively turning their brains into mush. There is no cure.

Do you know what happens if a farmer’s sheep test positive for scrapie? The entire herd is culled, as soon as possible, sometimes even sheep from surrounding farms as well. All sheep that have stayed at the infected farm will also be culled. The farmer won’t be permitted to have sheep on the farm for a certain period of time and must destroy all their hay. For the next ten years, every visitor to the barns will have to be notified of the danger of infection. 

The local veterinarian decides what needs to be disposed of and what can be sanitised. And we’re not talking only about equipment but whole barns. The barns and everything in them must be disinfected with strong chemicals or fire and everything must be repainted. Finally, the soil around the barns is exchanged for new material and the area is paved. The government pays some damages, but it’s not likely that they will cover the financial loss, let alone the emotional damage of having your life’s work methodically wiped out – let alone the death toll. 

The only person 

When Karólína Elísabetardóttir visited Iceland for the first time, she fell in love with the country, its nature, and the animals; horses and sheep. It was a coincidence that led her, some years later, to buy some land and start a farm. Located halfway up a mountain pass in North Iceland, her estate is large but mostly consists of a mountain and a river. It hadn’t been farmed for over a century so there are no cultivated fields. When asked if she ever gets lonely on her mountaintop, Karólína simply replies: “I’m not alone, I’m just the only person.” Her four horses, two dogs, and herd of sheep keep her company. They also provide her livelihood. She raises her sheep for their wool and provides the opportunity for people to foster sheep. In exchange for their patronage, they receive a fleece of wool each spring, when Karólína ships wool in all the colours of a sheepish rainbow to her customers. Since she isn’t worried about meat production, she has the freedom to breed tall and lean sheep, which make them better equipped to navigate her mountainous land, and while many wool farmers prefer white sheep, she looks for interesting colours. It takes years to breed a herd to a farmer’s specific liking. One unfortunate contact with an infection could bring her back to square one. 

He’s a born and bred farmer, the sixth generation of his family living in Sveinsstaðir, along with his wife Inga Sóley Jónsdóttir.

A farmer by blood 

Ólafur Magnússon is a farmer at Sveinsstaðir in North Iceland, a 40-minute drive from Karólína’s mountain. He’s a born and bred farmer, the sixth generation of his family living in Sveinsstaðir, along with his wife Inga Sóley Jónsdóttir. His ancestral home was built in 1929 and his herd of sheep are the direct descendants of sheep brought there in the 1940s. Until he lets them out to pasture in spring, they reside in a bright and airy barn, recently tripled in size. In contrast to Karólína’s sheep, the group mostly consists of white sheep and almost every one of them has horns. “Every farmer has his own quirks like that,” Ólafur tells me. “I think the horned sheep are the prettiest, but others prefer the look of polled sheep.” 

Sveinsstaðir has never had a case of scrapie, nor have the surrounding farms, despite the disease being endemic in the region. In the next valley over, however, Ólafur knew a farmer facing the constant threat of the disease as it popped up on farms all around them. “If it didn’t happen this autumn, they had to be prepared for it to rear its head next year, or the year after that. You can’t really focus on developing your breeding program or your farm with this hanging over you.” 

He’s a born and bred farmer, the sixth generation of his family living in Sveinsstaðir, along with his wife Inga Sóley Jónsdóttir. 

Figuring it out 

About a year ago, Ólafur got a message from Karólina. Despite the relatively short distance between their farms, he didn’t know her personally. But Karólína had been reading up on scrapie. She knew what a scrapie infection would mean and she wasn’t too keen on having that happen on her own farm, where her herd of sheep was so entwined to her life that they would come when she calls them. And if it wasn’t evident from the life she had carved out for herself on her mountain, if Karólina set her mind to something, things got done. “I thought that there must be another way,” Karólína told me. She read up on the research Stefanía had done in Keldur. In fact, she read everything she could find on the subject. “I know some veterinarians and sheep farmers in Germany and other countries and that was the reason that I started looking into the genotypes.” 

Digging through DNA 

Through her contacts, she got in touch with Christine Fast in Greifswald, Germany. They talked about the attempts to find the ARR genotype in Iceland. While no such sheep had been found in the first study, the word among farmers was that there might be something there. There was no research to support it, but some farms seemed to be shielded from scrapie cases, even though the disease was popping up all around them. “Then, Christine told me that there might be something else.” There was some evidence suggesting that they could look beyond the three codons usually studied to determine scrapie susceptibility and look for differently composed genotypes that might prove scrapie-resistant. “It was a spot of luck really, that at the same time, I found a report on research conducted in Italy, three studies that were carried out fifteen years ago,” Karólína says. “They found that a specific genotype that they called T137 seemed to be as resistant to scrapie as ARR.” This sparked something in Karólína’s brain. “I had read in Stefanía’s report from the scrapie study conducted in Iceland two decades ago, that T137 had been found in Icelandic sheep.” If they could find more of these sheep, there might be some hope. But that study had been made 20 years ago. Since then, several cases of scrapie had been discovered and several whole herds culled. Since 1996, 61 cases of scrapie had been detected on 58 farms in Iceland.

A looming threat 

Karólína’s farm is in a designated scrapie region. It means that farms in the area regularly encounter outbreaks of the disease. In fact, this is the region where scrapie was first detected. In the late 19th century, an English ram was imported to Iceland via Denmark. It was a beautiful ram with many desirable qualities that farmers were excited to introduce to their own herds. But they got more than they bargained for: scrapie. Importing live sheep was banned in Iceland in 1882. Occasionally, over the following century, exemptions were made. In all but one of those cases, new diseases were introduced to Icelandic sheep. The last attempt was made in 1945, but the sheep were culled when found to suffer from footrot. 

A way out

Now there’s a light at the end of the tunnel: breeding. At the turn of the millennium, studies found that some sheep are naturally resistant to scrapie. They can’t catch it. The reason is embedded in their DNA, as susceptibility for scrapie is determined by genes. A simple test reveals the polymorphism of three codons, 136, 154, and 171, which determine scrapie susceptibility. Each codon is assigned a letter. VRQ makes sheep very susceptible to scrapie, while ARR protects them from catching the disease or passing it on. For the past two decades, farmers in mainland Europe have bred their herds to contain ARR genotypes, preventing scrapie from taking hold. Once this information was available, veterinary scientists at Iceland’s Institute for Experimental Pathology at Keldur, including Stefanía .orgeirsdóttir,  launched a study assessing the genes of Icelandic sheep, the only breed in the country. The results were disheartening. No ARR sheep were to be found, meaning no ARR protection could be bred into Icelandic herds. Options to fight scrapie in Iceland would continue to be limited – either import ARR sheep from other countries, and risk introducing new diseases to the isolated island breed, or a zero-tolerance approach to scrapie cases. Until now, the scorched earth approach has won out.

THE SIX SHEEP AT 

SVEINSSTAÐIR THAT CARRY 

THE PROMISING GENOTYPE.

A needle in a haystack 

“I got a call from Karólína last spring, asking me to take samples from some sheep in my herd,” Ólafur tells me. His herd counts around 770 sheep. “I wasn’t really sure how to choose which sheep to test but I tried to cover a range of family lines,” Ólafur tells me. He took 20 samples, which were then taken to Reykjavík and to Germany to be tested. Even though T137 had been found in Stefanía’s earlier research, Gesine’s sequencing soon proved that it was rare in Iceland. From the first sample batches, no T137 cases were found. But back in Sveinsstaðir, Ólafur discovered that a couple of samples had been left behind, never making it  to Germany. They got shipped with the next batch. One of the samples was from a ewe called Trú, which translates as Faith. They’d hit the jackpot. Trú carried the T137 genotype. A matriarch of a long line of ewes, further testing at the farm produced five more sheep. Tignarleg, Trygglind, Trygg, Tombóla, and Tara all carried the promising genotype. This year, lambing season starts around Easter, and the six sheep at Sveinsstaðir farm are expecting a total of 16 lambs, which will hopefully be the start of something even bigger. “We’re ecstatic. Farmers have been waiting for good news like this for the longest time,” Inga tells me with a smile. “We’re simply so grateful for this woman.” The T137 genotype still presents some issues. While the ARR genotype is internationally recognised as scrapie-resistant, much less research has been done on T137. And although six sheep were found in Sveinsstaðir, all of them are ewes, so fingers are crossed that some of the sixteen lambs this spring will be rams, ready to spread their seed across the country for a good cause. But the study wasn’t over. It still had one lucky coincidence up its sleeve. 

Jackpot 

When 4,200 samples had been processed over ten months, it was time for sheep from Þernunes farm in Reyðarfjörður, East Iceland. Nine sheep carrying the prized ARR genotype were discovered. This time, most of the nine were polled, in stark contrast to Ólafur’s six horned sheep. 

There are more than around 400,000 sheep in Iceland. So far, a couple dozen of them have been found to carry genotypes resistant to scrapie. Finding the sheep is not a solution in and of itself, but only the first step in a massive breeding project in the years to come. Eyþór Einarsson, the sheep breeding consultant with the Agricultural Advisory Centre, tells me that the task ahead is daunting. To start with, they’ve only found one ram with a resistant genotype so far. Furthermore, that ram lives in a region where scrapie has been detected, and there are strict regulations in place limiting breeding options for such sheep. Still, the study is far from over. Farmers across the country were invited to submit samples from their own sheep and over five hundred farmers have already participated. 

Breeding sheep is a complicated process and care must be taken to prevent inbreeding. But now that there is a solution in sight, the team wants to get started as soon as possible, especially following a recent surge in scrapie cases. “We want to do this as fast as we can, preferably without lowering our standards for inbreeding and without losing diversity in the breed. We haven’t faced a challenge like this before, but farmers are hopeful, and together, we’ll get this done.”

Research projects continue and enthusiastic farmers can now participate by having their sheep tested. Just before this issue of Iceland Review was sent to print, the research team had some good news. They’d discovered some sheep carrying the T137 genotype at Stóru-Hámundarstaðir farm – including another ram! 

Genetic Jackpot: the Icelandic Sheep that Could Eradicate Scrapie

sheep

Six sheep on the farm Þernunes in Reyðarfjörður, East Iceland, hold the key to eradicating the fatal disease scrapie from the country. RÚV reports that the sheep carry a gene that is recognised by the European Union to protect against the disease. This is the first time the genotype has been found in Iceland, and could be pivotal to winning the fight against the disease, which has plagued Icelandic farms for over a century.

The genotype, known as ARR, has never before been found in Iceland, despite great efforts from researchers. Another genotype known to protect sheep from scrapie, known as T137, was also recently found in at least four Icelandic sheep. Extensive research in Italy has found that T137 protects sheep from scrapie, but it is not officially recognised by the EU as the ARR genotype.

Scrapie is a degenerative and fatal disease that affects sheep. Because it is highly contagious and can persist in flocks for decades, a flock in which the disease is discovered must be culled. Within the European Union, sheep that carry the AAR genotype do not need to be culled, even when scrapie is diagnosed within their flock, as research shows the gene protects them from both contracting and transmitting the disease.

Read More: Dream of a Scrapie-Free Iceland

Researchers sequenced 4,200 DNA samples from sheep around Iceland and sheep in Greenland that were of Icelandic origin. The six sheep in Reyðarfjörður that carry the gene trace their lineage to Reykhólasveit and Strandir, in the Westfjords, giving researchers hope the ARR genotype is to be found elsewhere in Iceland. Researchers plan to analyse DNA samples from some 15,000 sheep this winter to determine whether they carry the genotype.

The ARR genotype could eradicate scrapie through careful breeding. Researchers say, however, that it will be a challenge to spread the genotype through the population as quickly as possible without reducing diversity in the Icelandic sheep stock.

Sheep With Rare Genotype Could Eradicate Scrapie

Sheep that carry special genes could hold they key to eradicating the fatal disease scrapie from Iceland, RÚV reports. The ewes Tignarleg, located on a farm in Northwest Iceland, and Móbotna, on a farm in the northeast, both carry a rare gene that protects them against the fatal, degenerative disease. So far, four ewes that carry the gene have been found in the Icelandic sheep stock, but no rams. The findings are part of an international study that is providing hope that scrapie could be eradicated from Iceland within the next decade.

The Icelandic Agricultural Advisory Centre is taking part in the study alongside experts from Germany, England, and Italy. Guðfinna Harpa Árnadóttir, chairperson of the National Association of Sheep Farmers and a farmer herself, says that the genotype, known as T137, has been found to protect sheep against scrapie in three large Italian studies. “So we have hopes that the same applies to the scrapie that has been plaguing us here in Iceland. But it is yet to be confirmed by further research. But it’s very exciting, at the least, to find that genotype,” Guðfinna stated. 

Read More: Dream of a Scrapie-Free Iceland May Become a Reality

Móbotna, who belongs to Guðfinna, not only carries the rare genotype, but also sports rare colouring and has four horns. Guðfinna says researchers are seeking out sheep with unusual characteristics, as it might indicate they are more likely to carry rare genes. “Hopefully we’ll find more exciting animals that can help us in this fight against scrapie. Of course, in continuation, a breeding plan will be made, about how we plan to cultivate [the genotype] further.”

Scrapie is believed to have arrived in Iceland via an English ram that was transported to Skagafjörður fjord in 1878. It is a fatal, degenerative disease with no treatment or cure and it is highly contagious (between sheep). The prion that causes it can persist in soil and flocks for decades. Scrapie is not transmissible to humans.