Duck viral hepatitis(DVH) is a highly mortal disease and spreads rapidly in six-week-old ducklings.It is caused by duck hepatitis virus type I(DHV-1). The virus mainly infects the ducklings between two-day-old and three-week-old,but the adults have some resistance to the disease.The mortality rate is different from 15%to 95%in different ages.The duckling resisted the disease could not grow up any more.In recent years,the scientists of China have made great successes in the dianosis and prevention of ...