(AP) - The state of Nebraska added 10 more herds to its bovine tuberculosis quarantine list, bringing the total to 42, according to the Associated Press.

State agriculture director Greg Ibach said Tuesday the quarantine expanded because some of the restricted herds sold cattle before the quarantine was imposed. Ten Nebraska counties now have quarantined herds, up from five last week. And Colorado and South Dakota officials have been alerted.

Ibach said state and federal officials have confirmed only two cases of the disease in one Rock County herd. The other 41 quarantined herds either may have had fence-line contact with the infected herd or bought animals from a quarantined herd. The 42 Nebraska herds are in Boyd, Brown, Cedar, Colfax, Gage, Holt, Keya Paha, Loup, Pierce and Rock counties. None of the quarantined herds can sell cattle unless they obtain a special permit for immediate slaughter.

The U.S. Department of Agriculture is working with state officials to determine the source of the tuberculosis and how widespread the infection is. The outcome of that investigation could create a significant disadvantage for Nebraska's roughly $10 billion cattle industry. If the state loses the tuberculosis-free label it’s held for the past 17 years, Nebraska producers might have to pay to test their cattle and prove they are disease free before shipping them to other states.

Source: Associated Press