New bison calf rounds off genetically pure Fort Collins herd

Rachel Musselmann

[new_royalslider id=”333″]

Photos by Rachel Musselmann.


Born this month, a tawny bull calf is one of the final members to join a local bison herd set to be released into Soapstone Prairie.

“This birth is a good indicator,” said Jack Rhyan, a veterinarian with the U.S. Department of Agriculture. “It looks very likely that these animals will be able to do well in Soapstone.”

The bison, direct descendants of genetically pure Yellowstone bison, have been carefully purged of brucellosis, a disease that can cause problems with pregnancy and induce abortions. Like several before him, the new calf was born using assisted “cleaned” reproduction techniques designed to remove disease from genetic material. The process was developed at Colorado State University by geneticist Jennifer Barfield.

“This is really unique reproduction technology,” said Meegan Flenniken of Larimer County Resource Management. “We actually clean the (sperm and eggs) from the genetically pure bison, then deposit them in a non-genetically pure, (brucellosis-free) surrogate mother.”

Rhyan said the Yellowstone bison were selected for this project because they lack the domesticated cattle genes found in many bison today. However, Yellowstone is one of the few areas in the United States still affected by brucellosis.

“We want to eradicate this disease entirely,” Rhyan said. “It can be transmitted to elk, cattle and humans in the form of undulate fever.”

The herd is a joint project between CSU, the USDA, the City of Fort Collins and Larimer County. It is part of an ongoing effort to reintroduce native species into Soapstone Prairie.

“This isn’t just about the bison,” said Daylan Figgs, program manager of Fort Collins Natural Areas. “It’s about a pretty unique partnership coming together.”

The reintroduction has been planned by the four organizations since 2008, Figgs said.

“Our ultimate goal is to grow the herd past the initial 12 members and spread new calves to other conservation herds,” Flennikan said.


Currently, the bison are housed at CSU foothills campus. The release date is currently set for Nov. 1 on National Bison Day.

There will likely be a public celebration welcoming the animals back to the area, and the herd will contain two more youngsters to be born in July, Rhyan said.

For now, the new calf seems to be enjoying his position as the only bull in the herd, according to Rhyan.

“He appears to be very healthy,” Rhyan said. “He’s romping all around, having fun and waiting for his new playmates to appear.”

Collegian Senior Reporter Rachel Musselmann can be reached at or on Twitter @rmusselmann