VOA慢速英语 2007 0206a（在线收听） |
| This is the VOA Special English Agriculture Report. The parasites 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 intestines. 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 Parasitic 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 parasite vaccines against coccidiosis. But the coccidia parasite is increasingly resistant to drug treatment. Also, some of the drugs used to treat the disease are antibiotics. 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 defense system to release chemicals that fight the parasites. Mushroom lectin is injected into chicken embryos. The lectin is also added to drinking water for chickens. The team used a lectin from a mushroom found mainly in the stumps of black locust 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 Poultry 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. Transcripts and audio files are at www.unsv.com. I'm Steve Ember. |
| 原文地址：http://www.tingroom.com/voa/2007/2/39983.html |