This is the VOA Special English AGRICULTURE REPORT.
American scientists have produced an exact copy of a bull that was naturally resistant to three infectious diseases that affect cows. The calf is believed to be the first animal cloned for disease resistance.
Research scientists at Texas A-and-M University in College Station showed the calf to reporters last month. They say the research could lead to safer beef products and help farmers around the world.
The calf was produced from genetic material taken from an animal named Bull Eighty-Six. Scientists studied Bull Eighty-Six as part of a program supervised by Texas A and M University and the Texas Agricultural Experiment Station. Tests showed that the bull was naturally resistant to three diseases. They are brucellosis, tuberculosis and salmonellosis.
All three are bacterial diseases that can harm both animals and humans. They can spread from one group of cattle to another. And all three diseases can be passed to humans through the meat or milk of diseased cows.
Fifteen years ago, scientists took cells from the ear of Bull Eighty-Six. They froze the cells for future genetic study. Now, the researchers successfully used the cells to produce an exact copy of the animal. They say this was the longest time that genetic material had been frozen and later used for cloning.
The young bull is named Bull Eight-Sixty Squared. Genetic tests have shown that he is an exact copy of Bull Eighty-Six. The researchers believe tests will show that the young bull also has the same resistance to the three diseases.
If so, they will begin cloning the young bull and breeding him with cows to produce baby cows. They want to see if the disease-resistant genes can be passed on. The goal of the research is to produce disease-free cattle. This would improve cattle-raising and provide more beef for the world.
Experts have tried several methods to end the threat of infectious diseases in farm animals. They include testing animals, vaccinating them to protect against disease and destroying infected animals. However, nothing has been successful in ending cattle diseases.
The Texas researchers say their experiment may help farmers in many countries who cannot pay for vaccinations or test their animals for diseases.
This VOA Special English AGRICULTURE REPORT was written by George Grow.