Millie, the cow cloned by the University of Tennessee Institute of Agriculture, was found dead in a pasture early June 4.
The animal, the first Jersey calf clone from an adult somatic cell, drew international attention after her birth August 23 last year.
A UT employee checking the herd around midnight found the cow dead. No other animals in the herd were harmed.
UT veterinary pathologists who performed the necropsy on Millie found no visible abnormalities. Tissue samples were taken for toxicological studies.
-Her death was so totally unexpected,- said Dr. Lannett Edwards, head of the UT Cloning Project. -It-s frustrating because we have found nothing that would account for why she died.-