First successful embryo transfer in wood bison
University of Saskatchewan veterinary scientists and colleagues across Canada have recently carried out the world鈥檚 first successful embryo transfer in wood bison.
In mid-June, two wood bison calves were born at the university鈥檚 Native Hoofstock Centre, 16 kilometres southeast of Saskatoon.
Success was achieved after four years of work with researchers from University of Calgary, theNorthwest Territories, and the Calgary and Toronto zoos.
鈥淎side from being a first for Canadian researchers, it really shows that we can produce disease-free, healthy wood bison using this model,鈥� says U of S researcher Dr. Gregg Adams, who led the project.
鈥淎lso, anything we learn about wood bison is very likely translatable to plains bison, which is important in raising plains bison for parks or agricultural products.鈥�
Dr. Manuel Palomino, a graduate student fromPerupursuing his PhD in reproductive science and medicine at the Western College of Veterinary Medicine (WCVM), was part of the team.
鈥淭his has been a great opportunity for me,鈥� he says. 鈥淚鈥檝e learned new skills that I wouldn鈥檛 have been able to develop in my country due to the lack of facilities, equipment and even researchers.鈥�
Found mainly in Alberta鈥檚 Wood Buffalo National Park and in the Northwest Territories, the wood bison population has been drastically reduced due to two infectious bacterial diseases that can affect mammals and humans鈥攂rucellosis and tuberculosis (TB).
鈥淲ood bison are considered a threatened Canadian species,鈥� Palomino said. 鈥淚t鈥檚 very important to maintain this emblematic animal withinCanada.鈥�
In 1985,Canadawas declared free of brucellosis and TB in domestic livestock, but these diseases continue to infect the wood bison population.
To avoid transmission to domestic cattle and otherwise uninfected wood bison, federal environment officials recommended that the diseased population inWoodBuffaloNational Parkbe eradicated.
The goal of the embryo transfer research is to replace existing herds with healthy wood bison with similar genetic make-up.
In 2006, a small herd of bison was donated to the U of S byAlberta鈥檚ElkIslandNational Park. A WCVM research team began detailed ultrasound examinations of the females to better understand the normal reproductive pattern of this wild species.
Palomino鈥檚 primary role in the project was to synchronize the ovarian follicle growth among the female bison so they鈥檇 be ready for embryo collection at about the same time.
鈥淚鈥檝e had previous experience using follicular ablation鈥攁n accurate technique for re-synchronizing the development of ovarian follicles,鈥� he says.
The procedure essentially resets the ovaries to zero. Then the team gives hormonal treatments to the female bison, stimulating multiple follicle development and superovulation.
Artificial insemination is then performed, and seven days later, researchers harvest the fertilized eggs (embryos) from the donor female鈥檚 uterus for transfer into a healthy recipient.
Last fall, the team attempted embryo transfer for the first time using fresh embryos鈥攁nd the bison calves were the successful result.
鈥淭he techniques are here鈥攚e now know that it鈥檚 possible to produce viable embryos in wood bison,鈥� says Palomino.
The next challenge is to attempt embryo transfer using frozen embryos. Researchers ultimately hope to store a whole herd of embryos in liquid nitrogen for future re-population of wood bison.
Investigators also plan to use their innovative approach鈥攕ynchronization of ovarian follicle development followed by hormonal treatments鈥攖o lengthen the wood bison鈥檚 breeding season.
鈥淲e鈥檇 like to get the bison cycling throughout the year so we can collect embryos year-round,鈥� says Palomino.
Provided by University of Saskatchewan
