VOA慢速英语 2007 0206a

This is the VOA Special English Agriculture Report.


The parasites² can spread from chicken to chicken through infectious droppings

The chicken industry loses billions of dollars worldwide because of a disease called coccidiosis. Coccidiosis is caused by parasites. The single-cell organisms infect and destroy cells in the intestines³.

Infected chickens lose weight from the disease. Less body weight means economic losses for producers. The disease spreads from bird to bird through infectious droppings. Sometimes infected chickens die from the disease. The infection causes diarrhea, and infected animals may not want to eat. Other kinds of animals, including cows, also get coccidiosis.

But research by Hyun Lillehoj and her team could offer a new way to reduce losses from the disease. Hyun Lillehoj is an immunologist in the Agricultural Research Service of the United States Department of Agriculture. She works in the Animal Parasitic⁴ Diseases Laboratory in Beltsville, Maryland. She led a team of scientists from research centers in South Korea.

She says many producers traditionally use drug treatments and live parasite¹ vaccines⁵ against coccidiosis. But the coccidia parasite is increasingly resistant⁶ to drug treatment. Also, some of the drugs used to treat the disease are antibiotics⁷. Many people are concerned about antibiotics in animals because of the increasing problem of drug resistance in humans.

The new method uses proteins from mushrooms. The proteins are called lectins. The lectins cause an animal's own defense⁸ system to release chemicals that fight the parasites. Mushroom lectin is injected into chicken embryos⁹. The lectin is also added to drinking water for chickens.

The team used a lectin from a mushroom found mainly in the stumps¹⁰ of black locust¹¹ trees. The researchers injected the lectin into eighteen-day-old embryos. When the chickens came out of their eggs, the scientists infected them with parasites to test the treatment. The team reported in Poultry¹² Science magazine last year that the treatment protected the chickens against weight loss. It also reduced the number of live parasites in their waste.

Hyun Lillehoj and her team are seeking patent protection for the natural control method they developed. She tells us that she and her team are also looking for companies to work with to further develop it.

This VOA Special English Agriculture Report was written by Jerilyn Watson. Transcripts¹³ and audio files are at www.unsv.com. I'm Steve Ember.

1 parasite   

n.寄生虫；寄生菌；食客

参考例句：

• The lazy man was a parasite on his family.那懒汉是家里的寄生虫。
• I don't want to be a parasite.I must earn my own way in life.我不想做寄生虫，我要自己养活自己。

2 parasites   

寄生物( parasite的名词复数 )； 靠他人为生的人； 诸虫

参考例句：

• These symptoms may be referable to virus infection rather than parasites. 这些症状也许是由病毒感染引起的，而与寄生虫无关。
• Kangaroos harbor a vast range of parasites. 袋鼠身上有各种各样的寄生虫。

3 intestines   

n.肠( intestine的名词复数 )

参考例句：

• Perhaps the most serious problems occur in the stomach and intestines. 最严重的问题或许出现在胃和肠里。 来自辞典例句
• The traps of carnivorous plants function a little like the stomachs and small intestines of animals. 食肉植物的捕蝇器起着动物的胃和小肠的作用。 来自辞典例句

4 parasitic   

adj.寄生的

参考例句：

• Will global warming mean the spread of tropical parasitic diseases?全球变暖是否意味着热带寄生虫病会蔓延呢？
• By definition,this way of life is parasitic.从其含义来说，这是种寄生虫的生活方式。

5 vaccines   

疫苗，痘苗( vaccine的名词复数 )

参考例句：

• His team are at the forefront of scientific research into vaccines. 他的小组处于疫苗科研的最前沿。
• The vaccines were kept cool in refrigerators. 疫苗放在冰箱中冷藏。

6 resistant   

adj.(to)抵抗的，有抵抗力的

参考例句：

• Many pests are resistant to the insecticide.许多害虫对这种杀虫剂有抵抗力。
• They imposed their government by force on the resistant population.他们以武力把自己的统治强加在持反抗态度的人民头上。

7 antibiotics   

n.（用作复数）抗生素；（用作单数）抗生物质的研究；抗生素，抗菌素( antibiotic的名词复数 )

参考例句：

• the discovery of antibiotics in the 20th century 20世纪抗生素的发现
• The doctor gave me a prescription for antibiotics. 医生给我开了抗生素。

8 defense   

n.防御，保卫；[pl.]防务工事；辩护，答辩

参考例句：

• The accused has the right to defense.被告人有权获得辩护。
• The war has impacted the area with military and defense workers.战争使那个地区挤满了军队和防御工程人员。

9 embryos   

n.晶胚；胚，胚胎( embryo的名词复数 )

参考例句：

• Somatic cells of angiosperms enter a regenerative phase and behave like embryos. 被子植物体细胞进入一个生殖阶段，而且其行为象胚。 来自辞典例句
• Evolution can explain why human embryos look like gilled fishes. 进化论能够解释为什么人类的胚胎看起来象除去了内脏的鱼一样。 来自辞典例句

10 stumps   

（被砍下的树的）树桩( stump的名词复数 )； 残肢； （板球三柱门的）柱； 残余部分

参考例句：

• Rocks and stumps supplied the place of chairs at the picnic. 野餐时石头和树桩都充当了椅子。
• If you don't stir your stumps, Tom, you'll be late for school again. 汤姆，如果你不快走，上学又要迟到了。

11 locust   

n.蝗虫；洋槐，刺槐

参考例句：

• A locust is a kind of destructive insect.蝗虫是一种害虫。
• This illustration shows a vertical section through the locust.本图所示为蝗虫的纵剖面。

12 poultry   

n.家禽，禽肉

参考例句：

• There is not much poultry in the shops. 商店里禽肉不太多。
• What do you feed the poultry on? 你们用什么饲料喂养家禽?

13 transcripts   

n.抄本（ transcript的名词复数 ）；转写本；文字本；副本

参考例句：

• Like mRNA, both tRNA and rRNA are transcripts of chromosomal DNA. tRNA及rRNA同mRNA一样，都是染色体DNA的转录产物。 来自辞典例句
• You can't take the transfer students'exam without your transcripts. 没有成绩证明书，你就不能参加转学考试。 来自辞典例句