LINCOLN, NEBRASKA — A herd of beef cattle has tested positive for tuberculosis in north-central Nebraska's Rock County, according to animal health authorities.

A news release from the Nebraska Department of Agriculture indicates the department and the U.S. Department of Agriculture are working with the herd owner to quarantine and conduct more tests to determine the source and magnitude of the outbreak.

The herd size is not known and authorities are determining exactly how many cattle have tested positive.