An artificial insemination (AI) procedure undertaken at Toronto Zoo has seen 2 wood bison calves born. What’s amazing is that the father of the second calf actually lived on Elk Island, Alberta during 1980 at which point a sperm sample was collected. The use of this sperm represents the longest storage time for any sperm successfully used in an AI procedure leading to the birth of a zoo animal.
Curator of Reproductive Programs and Research for Toronto Zoo, Dr. Gabriela Mastromonaco said, “This is an excellent example of genetic material used over “time and space”: the infusion of genetics into a herd many years after the donor is gone and translocation of genetics between locations.”
These two calves were born on July 21st and 28th 2015. One is important as his mother was one of the first six calves born through artificial insemination at the zoo.
Toronto Zoo has been involved in the captive breeding and wild reintroduction of wood bison since 1997. During this time the International Union of Conservation and Nature (IUCN) has downgraded them from “endangered” to “threatened.” Unfortunately the species still faces the threat of disease into the future.
One of North America’s few reproductive physiology labs is based out of Toronto Zoo. They have been conducting a research program into artificial insemination of wood bison for the past five years.
Dr. Mastromonaco explained, “We have been working on optimizing artificial insemination techniques in wood bison along with our collaborators at the University of Saskatchewan. This is the fifth year that we have had calves following the insemination of our wood bison females. We have been slowly improving the technique using only cooled sperm in the first two years, followed by frozen-thawed sperm for two years. Once we were able to get calves from frozen-thawed sperm, we felt confident in attempting an insemination with 35 year-frozen sperm.”
Photo Credit: Toronto Zoo
