29 January, 2013, Danielle Sisson
The constant drone of cicadas, the glassy heat rising from the bitumen, the uninterrupted blue sky and the sun radiating waves of shimmering and chiming warmth onto your back; a typical summer’s day in the Australian outback.
The stock move a little slower, a little more sluggishly, people’s faces soon grow red with minimal exercise, dams and rivers become inviting and a cold beer is the ultimate reward at the end of the day when the crickets come out to take over from the cicadas’ song. But it is also a breeding ground for trouble.
Flies wait for this season. And they don’t just target the steak and sausages on the barbeque, or people’s red and sun-warmed faces, they also become a real problem for livestock. The season of summer is also the season of flystrike for sheep.
Breech flystrike is where breeding flies lay their eggs in between the skin folds on the rear end of a sheep, where their young can be protected from the fluctuating environmental conditions. The maggots then grow and feed on the meat in their immediate environment – the sheep’s flesh. This is flystrike and this is a problem that both sheep and farmers have to deal with every summer.
During the warmer months, in locations where rainfall is also high, Australian merino sheep can succumb to flystrike. If the condition is not treated, it can cause them considerable discomfort and pain, and eventually death.
A preventative strategy to stop merino sheep becoming flyblown still used by the majority of sheep farmers today, is called mulesing. Mulesing is where skin is sliced from the rear end of a sheep to produce a scar that is free of wrinkles and wool. This part of the sheep is where urine and faeces build-up and further form a moist environment. Once this part is removed, the lack of an appropriate rearing ground for the maggots makes it difficult for these sheep to become flyblown.
Farmers are trying to use breeding decisions to decrease undesirable traits, such as the number of sheep that are likely to get flystrike. This is done by allowing sheep with traits that are advantageous to breed and culling those without those traits from the flock.
However, for sheep that still have a high chance of getting flystrike, mulesing can still be used, in spite of some pressure from consumers and bigger companies and organisations, such as from the People for Ethical Treatment of Animals (PETA). The push by PETA to stop mulesing in Australia had plenty of publicity, and this caught the attention of everyday Australian consumers. The major push by the sheep industry to stop mulesing appeared to come after PETA’s campaign.
Scientist from the University of New England’s (UNE) Animal Health Section, Associate Professor Lewis Kahn has research in the area of sheep parasites. Lewis thinks that while organisations such as PETA have some influence on our practices, a lot of the push for change is at the community level, or even from the farmers themselves.
“I think the effort to stop mulesing was to meet community expectations,” said Lewis.
“And if the community expectations were raising a concern that mulesing was no longer the most effective and accepted practice, then we need to be able to respond to community expectations. Organisations like PETA no doubt bring that to the forefront of the communities mind, but I also think that the industry has a good track record of trying to put together the practises that enable us to have good welfare as well, so I don’t think it was just PETA.”
“I think farmers do a reasonably good job now. Quite understandably, we [the Australian public] want agricultural goods that are being produced with a high welfare, that’s sold without residue and is ethical. And that is what the industry has been and continues to try to attempt all the time, but as society changes and our tolerance of various practice changes, we need to evolve to meet those. Farmers now are looking at putting much more pressure on genetics to make progress and therefore remove the need for mulesing entirely.”
New England Primary Producer Keith Dawson, owns 870 hectares of land around Armidale and runs sheep and cattle.
While Keith agrees with trying to look after his livestock with a high welfare standard, he thinks that some people who are adamantly anti-mulesing just don’t understand the issue.
“It’s generally thought that these people just don’t understand the consequences, that we’re trying to avoid the strike,” he said.
“You want to get some of these people when you’ve got a badly flyblown sheep, and you want to get them in while you trim them and take the wool off. I think they are just fully unaware of the seriousness of flystrike.”
For a while there, a phase-out of mulesing by the sheep industry was endorsed, which also tried to produce market-based incentives to encourage farmers to move onto relying on different practices. With the majority of sheep farmers still mulesing and the majority of companies that buy wool still not pushing for non-mulesed sheep, the economic encouragement has not yet made much of an impact on real-life practice.
“They talked of that but it’s not working,” Keith said.
“There was this incentive thing and they came around and inspected. The wool buyers, anyone that claimed their sheep had not been mulesed they came around and looked at the mob of sheep to make sure what they were getting was right.”
Keith currently has 1,900 breeding ewes, 700 sheep and 40 rams. He has spent 75 years working on the land. Because theNew England weather produces some good conditions for flystrike, Keith uses the preventative measure of mulesing on his sheep.
“We use mulesing every year. We have 5 men working on it; the last lot we did 700 in about three and a half hours,” he said.
“It’s not the best day of the year when we do it. It’s not fun. I mean we’ve been mulesing for I don’t know how many years, 20 years, I suppose, at least.
“We notice that a day or two afterwards they’re up feeding and everything. It’d be painful. It’s the short-term pain against the long-term benefit. You only have to mules a sheep once in their life.”
Before Keith began mulesing, there were bigger problems with flystrike. The wool on sheep with flystrike breaks away from the rest of the fleece, and cannot be sold. This means the farmer loses money not only on treatment, but also on the wool that gets ruined in the flyblown area. The rest of the fleece also can lose value because of that break with the flystruck area.
“We were treating them as we found them,” Keith says.
“But the ones that get flyblown are the ones that lie down behind a log, and you don’t see until the crows are about. So you’ve got to keep a very close eye on them. They walk around the paddock and it [the wool] falls off. So there’s a lot of economic loss. But the death of a sheep is the thing, because unless you’re around them every day or two, you’ll miss them. Once they get a bit of fly in them they go down. They sneak away.”
Keith and his son, who now manages the property, use a few methods to decrease the prevalence of flystrike. As well as mulesing, they apply a drench and shear and remove wool from the crutch of their sheep once a year, as well as trying to breed out sheep that are not prone to flystrike.
“We drench every month, and we shear the ewes in August and we shear the young sheep in October.
“It’s awkward because you’ve either got to bring the mob of sheep to the yards, we’ve got three sets of yards, but it’s still a nuisance. If you’ve got to do that you’re just not getting other jobs done.
“We try to avoid wrinkly rumped sheep to breed from so we are in a sense trying to breed away from anything that’s wrinkly and ‘fly-trappy’, so there is consideration in breeding.”
The majority of sheep producers in Australia still do use mulesing as a preventative strategy to minimise the risk of flystrike. The more consumer awareness and pressure about the issue, the more both farmers and scientists have been trying to come up with new ways of dealing with the problem. More and more information has been recorded, not just about sheep collectively, but about individual sheep and their genetic lines.
Paul Arnott is a property manager for the Armidale Group’s land in the same region as Keith. The Armidale Group is a collection of properties that are being run as normal farms, but with a research element to them as well. While Paul doesn’t mules on the current property, he has had to in the past.
“Mulesing is one of those cruel to be kind things. The consequence of flystrike is much more painful and difficult for the animal than mulesing,” he says.
Nowadays there is access to pain relief chemicals that is increasingly used by farmers who still mules.
“They use a spray on pain relief afterwards. So they mules the animal and spray it on with an analgesic spray and so that takes that pain away I suppose, for the initial part of it anyway. It’s not an operation you do just for the fun of it, it’s one of those things you’re doing to protect the sheep from flystrike, which is being eaten alive by maggots, which is worse than mulesing. In a lot of cases [flystrike’s] fatal, if they get blood poisoning,” Paul says.
Paul is in charge of about 9000 acres of land with the Armidale Group. As part of the Information Nucleus Flock project (INF), no mulesing is performed. The INF measures traits of sheep that they can then use to help work out if a sheep is going to produce young that has the desired traits for the area, such as low susceptibility to flystrike in a summer high rainfall area.
There are 8 sites around Australia which are measuring these traits, taken from sheep when they’re born, those sheep then breed two more lambs and the same measurements are taken from them. This INF research feeds into further refining the Australian Sheep Breeding Value (ASBV), a measurement of the genetic potential of the animal.
One example of the traits measured is fleece rot. Fleece rot contributes to flystrike as it makes that moist environment in which the maggots thrive. The ASBV for fleece rot can change depending on where the sheep live. For example, sheep from a drier summer area, such as in Western Australia, can have quite a good ASBV for the trait of fleece rot. However, if those same sheep are brought into a summer rainfall area, such as in the New England region, that ASBV can change for that particular trait because the environment is such a big factor in whether a sheep can get fleece rot or not. If there is no rain, there is no problem with wool being wet. This means the sheep is not as attractive for flies to reproduce on, and so those sheep will have less chance of getting flystrike
“The idea of [the ASBV] is we’ll be able to take a sample at lamb marking and within about 3 months they’ll have a good idea about the genetics of that sheep and how it will perform in the future,” Paul says.
“It means you can make all those culling decisions much earlier in the sheep’s life, so rather than having to wait until it grows out and has its lambs of its own and measure those lambs, you can measure that sheep now and decide whether it’s going to be a future keeper.”
Moving more into the research side of the issue, Lewis Kahn’s research in the Animal Health Section at UNE focuses on parasites and sheep. While flies are not usually though of as parasites, because their young are eating their host, the sheep, flies also fall under that category. The three main parasites that researchers at UNE are trying to protect sheep against are worms, flies and lice.
Flystrike is the second most costly animal health disease for the Australian sheep industry, he says. As well as those financial costs, there are other factors that are not as often considered.
“No one likes to go to bed worrying about animals, and as we know, all livestock farmers are always concerned about the welfare of their animals, and so there’s that risk factor as well.”
While sheep that get flystrike will become sick and can eventually die, there are some sheep that can develop a resistance and cure themselves with just their own immune response, rather than treatment with chemicals. These sheep are then often chosen for breeding the next generation to try to pass that resistance on to their young.
These breeding choices, or husbandry, are an important factor in reducing the prevalence of this disease. While farmers may not have access to genetic information on all their individual sheep, current research is gathering that information to put into databases and help farmers improve upon their husbandry decisions, such as with the ASBV system.
Producers have had to be able to tell if a sheep is a good or a bad one from just its physical appearance in the past, but databases like the ASBV system make information available that can cause a much faster change in traits, such as reducing flystrike susceptibility, by choosing the right genetic lines.
While male breeding sheep, called sires, have their genetic information used when making decisions about breeding, female breeding sheep, or ewes, are decided on depending on what they look like, their phenotype.
The sires genetic information can come from the ASBVs, and those values are used to select desirable traits that farmers want their young to inherit. If a potential sire is found to have low values in the traits that a farmer is aiming for, such as resistance to flystrike, they may not ever get the chance to reproduce.
While the industry is no longer pushing the phase-out of mulesing, it still supports the idea using of methods other than mulesing for controlling flystrike in sheep. Non-mulesing technology is slowly becoming more and more widespread. Farmers are trying to improve the welfare of their livestock, but until more technology is available, there are some short-term painful practices that may need to occur in order to stop long-term suffering for the animals.
For centuries, people on the land have been trying to improve the way they do things, improve the way they treat their livestock, because the livestock is their livelihoods. The industry of farming has come a long way in terms of humane treatment of animals, and it looks like they are willing to keep moving onto better management practices.
With farmers becoming more informed and having greater access to genetic information about their livestock, we may soon be able to witness the end of worrying about flystrike on those humid and wet to dry and scorching summer’s days.
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