DENVER (AP) — A purebred Yellowstone bison is living at the Bronx Zoo after scientists were able to successfully implant a genetically pure embryo into a commercial bison.
The zoo and Colorado State University announced Thursday that the surrogate bison gave birth to a healthy male calf at the zoo on June 20. The embryo was taken from a Yellowstone bison kept at the university in October, washed free of disease and implanted in the surrogate.
While many bison have been bred with cattle, Yellowstone National Park has one of the world's largest and most genetically-pure bison herds. However, about 40 percent test positive for exposure to brucellosis, which can cause pregnant animals to miscarry. Concern about the disease has prevented the animals from being taken out of the park to reproduce.