An unprecedented procedure could help to ensure the continued survival of the critically endangered species.
The last remaining male of the species, Sudan, was put down on Monday after several months of ill-health.
Conservationists have reported that the health of the last male northern white rhino is rapidly deteriorating.
After years of poaching, the world's population of northern white rhinos has been reduced to three.
The last remaining male northern white rhino has four armed guards protecting him 24 hours a day.
One of the last remaining northern white rhinos has died leaving only six left alive in the whole world.