A cow resistant to the damaging mastitis disease might save the dairy industry millions of dollars. Researchers at the University of Vermont (UVM) in the US have cloned a gene that kills the bacteria that causes certain forms of mastitis, a disease that inflames the mammary gland, Associated Press reports. ''Our work has led to the world's first mastitis-resistant animals,'' Dr. John Bramley, UVM's lead researcher and dean of the College of Agriculture and Life Sciences, said Wednesday. ''Tests show that the animals are perfectly normal, their milk supply is perfectly safe and their offspring grows well.'' U.S. Department of Agriculture scientists then cloned a Jersey cow, Annie, they hope will be resistant to the disease by secreting a protein called lysostaphin. Mastitis costs the dairy industry approximately $1.7 billion dollars a year in prevention, treatment and milk losses, the USDA estimates. About 30 per cent of all cases are caused by staphylococcus bacteria. However it could be a year before Annie the cow, born in March 2000, produces milk and can be tested for mastitis.