跟读练习: Disease Surveillance Part 4 - Porcine Reproductive and Respiratory Syndrome (PRRS) - 通过视频学习英语口语
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Hello my name is George Chalmers and today I'm here at SRUC Vet Centre near Craveston.
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I'm going to be talking to Pernay Jorgensen, a Veterinary Investigative Officer and today we're going to be talking about purrs and pigs,
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looking at the effects and also what farmers can do about it
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if they find they get it or how they can try and keep it out.
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Purs is the most economically damaging disease to pig herds in Scotland.
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It causes stillbirths and abortions in the breeding herd and also can lead to respiratory diseases in the growing herd.
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The control and eradication of Purs is vitally important for the Scottish pig industry.
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It will improve the health of the pigs obviously but also the efficiency and the economics of the sector.
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Not only will these areas benefit but a major consideration is
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that as the efficiency improves the carbon footprint of the Scottish pig sector will also improve.
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For more information please refer to the FAS website at faz.scot.
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PERS, also known as PRRS,
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stands for Pocine Reproductive and Respiratory syndrome and it's a viral disease in pigs worldwide.
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It's also been known as blue ear disease
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which sort of classifies the blue ears that some pig might develop when they get infected.
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The disease has been present in the UK since 1991 and in Scotland in 1992 and it's now endemic in the country.
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There are two types of virus, two genotypes of PERS.
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There's the type 1, PERS type 1, which is the European genotype and then there's the American one which is type 2.
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We only have PERS type 1, the European genotype in the country at the moment.
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Well, PERS is one of the most important diseases in Scotland
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and it's mostly present in the farms in the northeast of Scotland just because there's the most commercial farms in this area.
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A survey from the abattoir, it's a historic survey from the abattoir in 19,
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showed that about 44% of finishing farms had pigs with antibody in them.
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Pirs can affect pigs differently depending on their age and their immune system, and depending on whether it's a breeding herd and a finishing herd.
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As the name implies, It's called porcine reproductive and respiratory syndrome in pigs.
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So the main effects we see from a purse infection is reproductive issues in sows,
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which includes abortions, stillbirths, born of weak piglets,
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increase in pre-weaned mortality and return to oestrus.
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And the respiratory part is often pneumonia, interstitial pneumonia in growing pigs.
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In chronically affected herds you might see asymptomatic pigs
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which means they don't look particularly sick from Perse
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but they harbour the virus in their body
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which means they can affect other pigs
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and they can also become sick with other diseases because they become immunosuppressed by the virus.
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So they're quite prone to bacterial diseases on top.
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In more acutely affected herds if the Perth virus has ever been present before.
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They don't have an immune response to the virus
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and they will often go down with severe disease on the unit and that's sort of acute deaths due to fever.
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They have varimia, virus in the blood.
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They can get respiratory distress, diarrhea, weight loss and just death in all groups.
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So this might be a bit scary if that happens.
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It could resemble ASF coming into a herd, so it's important to do some further diagnostics to rule that out.
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PERS only affects pigs, domestic and feral, so wild boars can be infected too.
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And it cannot be transmitted to humans, not from live pigs or from meat products.
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Because it's mainly pigs who harbour the virus, the main way of getting introduction of the virus into a unit is by bringing in pigs.
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And that often in a breeding unit that would involve getting gills in or even boars as replacements.
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So it's important to make make sure that they are in quarantine and that you source them from PERS-free units.
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The virus can be found in all secretions, semen, saliva, blood, so it's important also to make sure that
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when you bring in bores that they are free from PERS
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and are quarantined and if using AI as your main method of service to make sure
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that they are certified free of PERS.
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The virus does not survive well outside the pig host,
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however there are other ways of transmitting purrs within a farm or between farms than by pig to pig contact.
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It can be transmitted by flies, slurry, infected slurry and even airborne and that's why
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important risk factor for purrs is proximity to other pig herds just because it gets spread by the wind.
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It can also be briefly be alive on infected clothes and vehicles, hence cleaning and disinfecting is important.
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Once PERS is in a unit it spreads really quickly by nose-to-nose contact between pigs.
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It can also be transmitted from the sow to her piglets and over the placenta when she's pregnant.
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And as discussed before it also can transmitted through the semen.
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So if there's insemination or service by an infected bore that can also cause infection.
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It's quite easy to diagnose spurs on a unit if it's suspected by the clinical science.
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We have many ways of diagnosing it mainly
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because the virus is present in all of secretions in the pigs which include semen, blood and saliva.
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So it doesn't even need a vet sometimes to take the actual samples
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because we can have chew ropes where we just place a rope
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within a pen and the the pigs can chew on it
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and then we can do a PCR at the lab which will detect virus.
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Other ways of diagnosing PERS would be to submit dead animals for post-mortem examination.
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That's especially a good idea if it's an acute death and we don't suspect PERS, mainly because we can't detect the interstitial pneumonia we see in growers
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unless we get a carcass and we can get the lungs for PCR testing and histopathology.
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We can also examine aborted fetuses for the presence of PERS virus.
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When PERS has been diagnosed in a farm it's important to
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talk to your vet about any strategies to control the disease on the unit.
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Each farm is different and have different needs and management systems, so it's important to refer with your vet and get a plan in action.
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Once a herd is diagnosed and infected, producers can go many ways to try and control the infection.
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Overall, the immune response of each of the herd and the individual pig is important for how the disease will develop.
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Once a herd is diagnosed with PERS, many choose to vaccinate as a way of controlling the disease within a herd.
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The vaccination serves two purposes.
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One is to reduce the clinical signs
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and the severity of the disease in the individual pigs so they don't die and get sick.
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And the second part is to ensure that they secrete as little virus as possible
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so they don't affect other pigs in the pens.
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In breeding herds, it's often protocol to vaccinate the sows, by which ways we protect the piglets through the colostrum.
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So they receive antibodies to the purrs when the sows and by which ways we protect the the piglets through the colostrum.
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So they receive antibodies to the purse when the sow is vaccinated which protects them until about six to eight weeks.
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At this time though the immune the passive immune system
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that they've sort of gained from the sow will wean
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and then sometimes it's recommended to also treat or sorry to vaccinate the the piglets themselves.
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Of course for this method to work it's important to ensure that the piglets always receive enough colostrum.
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The persistence of purse infection within a farm is reliable on two things.
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It's the presence of pigs who carry virus, who are chronically infected, and the bringing in of new naive pigs to the unit.
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So like we've discussed before that includes bringing in replacement gilts
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and having piglets born from sows who have never been exposed to virus
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and thereby mixing them with older pigs who might carry the virus.
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Improvement of the farm's biosecurity is also important to ensure
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that purse doesn't spread within a unit and outweigh the unit to neighbours and other farms.
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Keeping equipment and pens or just pig accommodation clean and disinfecting it in between batches is important to reduce the virus load.
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And also make sure that vehicles for transport
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and clothing in between different groups are kept clean so we don't spread it around.
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Fly control and avoid overstocking and good ventilation also helps reduce the pressure from the spread of the virus.
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Some people might consider with their vet to do a partial or full depopulation on the unit,
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but this is a big decision with many factors involved, so that's best discussed in detail with your vet.
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The Scottish pig industry is very interested in not just controlling pers as a disease, but to try and eradicate the disease on a national level.
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They've tried that by starting a pilot project which involved pig units in the Murray Coast area,
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where they tried to map out which farms had PERS and to try and control it.
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And the project worked really well and showed
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that a collaboration between the individual producers and the pig industry and vets and stakeholders
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is a good way to try and eliminate PERS on a national level.
为什么要通过这个视频练习口语？
通过观看和模仿这个与猪的生殖和呼吸综合症（PERS）相关的视频，您不仅可以提高英语口语练习的技能，还能增强对农业和兽医学的了解。这段视频展示了如何与兽医进行专业对话，讨论疾病控制的重要性，能够帮助您在类似的专业环境中自信地表达自己的观点。在口语练习中，进行shadow speech（阴影发声）可以有效提高您对话的流畅性和自信心，为将来参加雅思口语练习打下良好的基础。
语法与表达在上下文中的分析
- 被动语态: 视频中提到“PERS只影响猪”，使用了被动结构，使得专业术语更加正式与客观。
- 条件句: 在讨论控制疾病的策略时，使用条件句“如果发现感染，需要进行隔离”，强调了必要的步骤与结果之间的关系。
- 名词性短语: “经济损失”及“呼吸疾病”这些名词性短语的使用，能够清晰表达问题的严重性，适用于不同的专业讨论。
- 时间状语从句: “自1991年以来”这样的时间状语明确时间背景，帮助有效传达信息，并增强听众的理解。
常见发音陷阱
在这个视频中，有一些单词的发音可能会对学习者造成困难。比如“disease”（疾病）和“pneumonia”（肺炎），这两个词的发音有时容易混淆。请特别注意在发音时将音节清晰地分开。此外，“virus”（病毒）的发音与其他词类似，容易产生误解，因此需要特别练习。通过shadow speak（阴影发声），反复练习这些发音，能够帮助您在实际交流中提高英语发音的准确性，更加自然地与他人进行交流。
什么是跟读法？
跟读法 (Shadowing) 是一种有科学依据的语言学习技巧，最初开发用于专业口译员的培训，并由多语言者Alexander Arguelles博士普及。这个方法简单而强大：您在听英语母语原声的同时立即大声重复——就像是一个延迟1-2秒紧跟说话者的影子。与被动听力或语法练习不同，跟读法强迫您的大脑和口腔肌肉同时处理并模仿真实的讲话模式。研究表明它能显着提高发音准确性，语调，节奏，连读，听力理解和口语流利度——使其成为雅思口语备考和真实英语交流最有效的方法之一。