This herd is really neat. Bison have a disease called brucellosis which makes pregnancy nonviable and spreads to other species: https://www.nps.gov/yell/learn/nature/brucellosis.htm

Colorado State University pioneered an IVF technique to rid embryos of the disease and diversify their gene pool. They ship these healthy bison to various Native American tribal herds across the US and Canada for a progressive reintroduction of purebred bison to the Great Plains which evolved to have them as seasonal grazers.